Annual report pursuant to Section 13 and 15(d)

Income Taxes - Additional Information (Detail)

v3.19.1
Income Taxes - Additional Information (Detail) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2018
Dec. 31, 2017
Dec. 31, 2016
Income Taxes [Line Items]      
Income tax operating loss carryforwards $ 85.5    
Income tax operating loss carryforwards not expired 31.6    
Operating loss carryforwards expiration, 2019 0.0    
Operating loss carryforwards Expiration, 2020 0.0    
Operating loss carryforwards expiration, 2032 and beyond $ 41.9    
Federal income tax rates 21.00% 34.00% 34.00%
Minimum [Member]      
Income Taxes [Line Items]      
Income tax examination year under examination P3Y    
Maximum [Member]      
Income Taxes [Line Items]      
Income tax examination year under examination P5Y    
State and Local Jurisdiction [Member]      
Income Taxes [Line Items]      
Income tax operating loss carryforwards $ 12.0    
State carryforward period 20 years    
Federal and state [Member]      
Income Taxes [Line Items]      
Income tax operating loss carryforwards $ 73.5