Equity (Detail) - Share Repurchase Activity - USD ($) $ in Thousands	1 Months Ended	3 Months Ended
	Jan. 31, 2016	Mar. 31, 2016	Mar. 31, 2015
Stockholders' Equity Note [Abstract]
Number of shares repurchased (in shares)		466,823	4,084,590
Cash paid for repurchased shares during the quarter	$ 7,200	$ 45,487	$ 324,042