Equity - Share Repurchases (Detail) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Equity [Abstract]
Total Number of Shares Purchased	6,209,400	6,769,891	190,187
Total Cost	$ 100,630	$ 154,145	$ 7,653
Average Price Paid per Share	$ 16.21	$ 22.77	$ 40.24