Stockholders' Equity - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Sep. 23, 2015
Equity Class Of Treasury Stock [Line Items]
Stock-based compensation expense	$ 7,000,000	$ 7,100,000
Additional common shares issued under deferred and stock compensation arrangements	314,244
Purchases, shares	257,790
Long Term Incentive Plan
Equity Class Of Treasury Stock [Line Items]
Purchases, shares	8,856
Common Stock Repurchase Plan
Equity Class Of Treasury Stock [Line Items]
Purchases, shares	248,934
Stock repurchase program, authorized amount			$ 300,000,000