Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v3.19.1
Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Income Tax Contingency [Line Items]    
Effective corporate income tax rate 21.00% 35.00%
Deferred tax assets, valuation allowance $ 5,371 $ 6,154
Deferred tax assets, operating loss carryforwards, state and local   6,000
Deferred tax assets, impairment losses   $ 200
Valuation allowance 5,400  
Domestic Tax Authority [Member]    
Income Tax Contingency [Line Items]    
Net operating loss carryforwards for federal income tax purpose $ 148,100  
Beginning year of expiry for net operating loss carry forwards 2021  
Ending year of expiry for net operating loss carryforwards 2038  
State and Local Jurisdiction [Member]    
Income Tax Contingency [Line Items]    
Net operating loss carryforwards for federal income tax purpose $ 783,800  
Beginning year of expiry for net operating loss carry forwards 2019  
Ending year of expiry for net operating loss carryforwards 2038