Shareholders' Equity - Additional Information (Detail) - USD ($) $ in Thousands	2 Months Ended	12 Months Ended
	Feb. 22, 2016	Dec. 31, 2015	Dec. 31, 2014
Class Of Stock [Line Items]
Number of shares repurchased		5,000	294,000
Shares repurchased aggregate purchase price		$ 645	$ 22,817
Subsequent Event [Member]
Class Of Stock [Line Items]
Number of shares repurchased	241,000
Shares repurchased aggregate purchase price	$ 31,300
Number of shares authorized to be repurchased	1,200,000