Net Income (Loss) Per Common Share - Summary of Net Income (Loss) Per Common Share (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Line Items]
Net income									$ 40,518	$ 123,385	$ 26,762
Basic weighted-average common shares outstanding (in shares)									38,233	37,276	32,044
Effect of dilutive stock options (in shares)									61	288	612
Effect of dilutive performance restricted stock (in shares)									1,207	1,328	0
Diluted weighted-average common shares outstanding (in shares)									39,501	38,892	32,656
Basic income (loss) per common share outstanding (in dollars per share)	$ 0.35	$ 0.24	$ 0.25	$ 0.22	$ 2.58	$ 0.23	$ 0.37	$ 0.11	$ 1.06	$ 3.31	$ 0.84
Diluted income (loss) per common share outstanding (in dollars per share)	$ 0.34	$ 0.24	$ 0.25	$ 0.21	$ 2.47	$ 0.22	$ 0.35	$ 0.11	$ 1.03	$ 3.17	$ 0.82
Stock Options | Nonvested Restricted Stock
Earnings Per Share [Line Items]
Antidilutive securities excluded from diluted income (loss) per common share (in shares)									424	604	1,563