Stockholders' Equity - Additional Information (Detail) - USD ($)	Nov. 05, 2015	Dec. 31, 2017	Dec. 01, 2017	May 18, 2017	Jun. 02, 2016
2016 Stock Repurchase Program
Stockholders Equity [Line Items]
Share repurchase program authorized amount			$ 300,000,000		$ 100,000,000
Stock repurchase program additional amount authorized			$ 100,000,000.0	$ 100,000,000
Available amount under repurchase program		$ 113,300,000
2015 Stock Repurchase Program
Stockholders Equity [Line Items]
Share repurchase program authorized amount	$ 50,000,000
Stock repurchase program, period	6 months
Stock repurchase program expiration date	May 05, 2016