| Operating and Finance Lease Right-of-Use Assets (Tables)
 | 6 Months Ended | 
| Jun. 30, 2019 | 
|---|
| Leases [Abstract] |  | 
| Supplemental Balance Sheet Information Related to Leases | Supplemental balance sheet information related to leases was as follows: 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  | June 30, 2019 |  |  
|  |  | (Dollars in thousands) |  |  
|  |  | Related Party |  |  | Other |  |  | Total |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Operating leases ROU assets |  | $ | 10,085 |  |  | $ | 51,496 |  |  | $ | 61,581 |  |  
| Operating lease liabilities (current) |  |  | 993 |  |  |  | 8,658 |  |  |  | 9,651 |  |  
| Operating lease liabilities  (non-current) |  |  | 9,523 |  |  |  | 50,468 |  |  |  | 59,991 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Total operating lease liabilities |  | $ | 10,516 |  |  | $ | 59,126 |  |  | $ | 69,642 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  |  |  |  |  
| Weighted Average Remaining Lease Term |  |  |  |  |  
|  |  |  | 9.1 years |  |  
|  |  |  | 3.8 years |  |  
| Weighted Average Discount Rate |  |  |  |  |  
|  |  |  | 8.14 | % |  
|  |  |  | 4.31 | % |  | 
| Components of Lease Expense | The components of lease expense were as follows: 
|  |  |  |  |  |  
|  |  | Six Months Ended 
 June 30, 2019 |  |  
|  |  | (Dollars in thousands) |  |  
| Amortization of finance lease ROU Assets |  | $ | 55 |  |  
| Interest on finance lease liabilities |  |  | 5 |  |  
|  |  |  |  |  |  
|  |  |  | 60 |  |  
|  |  |  | 6,969 |  |  
|  |  |  | 472 |  |  
|  |  |  | 483 |  |  
|  |  |  |  |  |  
|  |  | $ | 7,984 |  |  
|  |  |  |  |  |  | 
| Schedule of other information related to leases | Supplemental cash flow information related to leases was as follows: 
|  |  |  |  |  |  
|  |  | Six Months Ended 
 June 30, 2019 |  |  
|  |  | (Dollars in thousands) |  |  
| Cash paid for amounts included in the measurement of lease liabilities: |  |  |  |  |  
| Operating cash flows from operating leases |  | $ | 7,038 |  |  
| Operating cash flows from finance leases |  |  | 8 |  |  
| Financing cash flows from finance leases |  |  | 43 |  |  
| Leased assets obtained in exchange for new operating lease liabilities |  | $ | 1,064 |  |  
| Leased assets obtained in exchange for new finance lease liabilities |  |  | 2 |  |  | 
| Schedule of Future Minimum Lease Payments | Future minimum lease payments required under leases that have initial or remaining  non-cancelable  lease terms in excess of one year as of June 30, 2019, are as follows:
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  | Operating Leases |  |  |  |  |  |  |  |  
|  |  | Related Party |  |  | Other |  |  | Total |  |  | Finance Leases |  |  | Total |  |  
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |  
|  |  | (Dollars in thousands) |  |  
|  |  | $ | 835 |  |  | $ | 6,342 |  |  | $ | 7,177 |  |  | $ | 41 |  |  | $ | 7,218 |  |  
|  |  |  | 1,696 |  |  |  | 12,930 |  |  |  | 14,626 |  |  |  | 66 |  |  |  | 14,692 |  |  
|  |  |  | 1,701 |  |  |  | 11,910 |  |  |  | 13,611 |  |  |  | 51 |  |  |  | 13,662 |  |  
|  |  |  | 1,680 |  |  |  | 10,323 |  |  |  | 12,003 |  |  |  | 43 |  |  |  | 12,046 |  |  
|  |  |  | 1,240 |  |  |  | 9,160 |  |  |  | 10,400 |  |  |  | 22 |  |  |  | 10,422 |  |  
|  |  |  | 7,519 |  |  |  | 39,164 |  |  |  | 46,683 |  |  |  | 3 |  |  |  | 46,686 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  | $ | 14,671 |  |  | $ | 89,829 |  |  | $ | 104,500 |  |  | $ | 226 |  |  | $ | 104,726 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  |  | (4,155 | ) |  |  | (30,703 | ) |  |  | (34,858 | ) |  |  | (16 | ) |  |  | (34,874 | ) |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  | $ | 10,516 |  |  | $ | 59,126 |  |  | $ | 69,642 |  |  | $ | 210 |  |  | $ | 69,852 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Reconciliation to lease liabilities: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
| Lease liabilities - current |  | $ | 993 |  |  | $ | 8,658 |  |  | $ | 9,651 |  |  | $ | 69 |  |  | $ | 9,720 |  |  
| Lease liabilities - long-term |  |  | 9,523 |  |  |  | 50,468 |  |  |  | 59,991 |  |  |  | 141 |  |  |  | 60,132 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  | $ | 10,516 |  |  | $ | 59,126 |  |  | $ | 69,642 |  |  | $ | 210 |  |  | $ | 69,852 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | 
| Schedule of Future Minimum Lease Payments Based on Former Accounting Guidance | Future minimum lease payments under leases that had initial or remaining  non-cancelable  lease terms in excess of one year as of December 31, 2018, based on the former accounting guidance for leases, were as follows:
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  | Operating Leases |  |  |  |  |  |  |  |  
|  |  | Related Party |  |  | Other |  |  | Total |  |  | Finance Leases |  |  | Total |  |  
|   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |   |  
|  |  |  |  |  | (Dollars in thousands) |  |  
|  |  | $ | 1,730 |  |  | $ | 11,633 |  |  | $ | 13,363 |  |  | $ | 58 |  |  | $ | 13,421 |  |  
|  |  |  | 1,763 |  |  |  | 11,592 |  |  |  | 13,355 |  |  |  | 39 |  |  |  | 13,394 |  |  
|  |  |  | 1,767 |  |  |  | 10,596 |  |  |  | 12,363 |  |  |  | 31 |  |  |  | 12,394 |  |  
|  |  |  | 1,730 |  |  |  | 9,490 |  |  |  | 11,220 |  |  |  | 27 |  |  |  | 11,247 |  |  
|  |  |  | 1,234 |  |  |  | 8,584 |  |  |  | 9,818 |  |  |  | 8 |  |  |  | 9,826 |  |  
|  |  |  | 13,364 |  |  |  | 48,109 |  |  |  | 61,473 |  |  |  | — |  |  |  | 61,473 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  | $ | 21,588 |  |  | $ | 100,004 |  |  | $ | 121,592 |  |  | $ | 163 |  |  | $ | 121,755 |  |  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |