Schedule I - Stockholders' Equity - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Feb. 22, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share Repurchase Program, authorized amount	$ 250,000,000
Repurchase of treasury stock, Shares	3,654,816
Stock repurchased during period, total cost	$ 98,032,000
Treasury stock at cost	$ 252,903,000	$ 154,871,000
Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	15,000,000
Shares available for future issuance	9,770,000
Parent Company [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Capital contributed to subsidiary from exercises of stock options	$ 4,230,000
Share Repurchase Program, authorized amount	$ 250,000,000
Repurchase of treasury stock, Shares	3,654,816	0	0
Stock repurchased during period, total cost	$ 98,000,000
Share Repurchase Program, remaining authorized repurchase amount	92,000,000
Treasury stock at cost	$ 252,903,000	$ 154,871,000
Parent Company [Member] | Subsequent Event [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock Repurchase Program, replenishment amount				$ 158,000,000
Share Repurchase Program, remaining authorized repurchase amount				$ 250,000,000
Parent Company [Member] | Omnibus Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved for future issuance	15,000,000
Shares available for future issuance	9,770,000