Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v3.20.1
Income Taxes - Additional Information (Detail) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2019
Dec. 31, 2018
Income Tax Contingency [Line Items]    
Valuation allowance $ 4,100 $ 13,000
Deferred tax assets, valuation allowance 12,977 $ 5,371
Deferred tax assets operating loss carry forwards domestic 28,600  
Deferred tax assets, operating loss carryforwards, state and local 8,900  
Deferred tax assets, valuation allowance provided 7,600  
Unlikey To Be Realised [Member]    
Income Tax Contingency [Line Items]    
Deferred tax assets 7,600  
Domestic Tax Authority [Member]    
Income Tax Contingency [Line Items]    
Net operating loss carryforwards for federal income tax purpose $ 136,100  
Beginning year of expiry for net operating loss carry forwards 2021  
Ending year of expiry for net operating loss carryforwards 2038  
Deferred tax assets, valuation allowance $ 4,100  
Deferred tax assets, valuation allowance provided 3,500  
State and Local Jurisdiction [Member]    
Income Tax Contingency [Line Items]    
Net operating loss carryforwards for federal income tax purpose $ 793,700  
Beginning year of expiry for net operating loss carry forwards 2020  
Ending year of expiry for net operating loss carryforwards 2039  
Deferred tax assets, valuation allowance $ 8,900  
Deferred tax assets, impairment losses 16,700  
Deferred tax assets, valuation allowance provided $ 4,100