Shares Repurchased - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Oct. 29, 2014
Equity, Class of Treasury Stock [Line Items]
Repurchased common stock, value	$ 24,116,000	$ 6,531,000	$ 1,613,000
Three-Year Share Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Common stock purchase authorized amount				$ 100,000,000
Repurchased common stock, shares	1,190
Repurchased common stock, value	$ 24,116,000
Repurchased shares, remaining for future purchases	$ 75,884,000
Three-Year Share Repurchase Program [Member] | Tax Withholding Obligations [Member]
Equity, Class of Treasury Stock [Line Items]
Repurchased common stock, shares		416	137
Repurchased common stock, value		$ 6,531,000	$ 1,613,000