Share Repurchase Program (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Mar. 31, 2016	Sep. 30, 2016	Sep. 30, 2015	Sep. 09, 2015
Equity Abstract
Share Repurchase Program authorized amount				$ 75,000
Treasury Stock Shares Acquired	324,141
Treasury Stock Acquired Average Cost Per Share	$ 37.96
Purchase of company stock	$ 12,300	$ 12,315	$ 0