Stockholders' Equity - Additional Information (Detail) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Dividend declared and paid per share			$ 0.20
Aggregate dividend declared for the year			$ 7,200,000
Authorized to purchase of common stock under the stock repurchase program		$ 535,000,000
Repurchase of common stock	100,000	0	200,000
Aggregate cost of repurchase of common stock	$ 5,300,000	$ 474,900,000	$ 9,600,000
Cumulative repurchase of common stock		16,300,000