Equity (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended					1 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jul. 31, 2013	Apr. 30, 2013	Jan. 31, 2013 2013 Stock Repurchase Program	Dec. 31, 2013 2013 Stock Repurchase Program
Number of shares authorized to be repurchased under the current open-market stock repurchase program						10,000,000
Repurchase of stock program, period						2 years
Number of shares repurchased under the current open-market stock repurchase program							4,285,695
Payments for shares repurchased under the current open-market stock repurchase program (in dollars)							$ 324,655
Quarterly dividend approved by Board prior to payment, per share (in dollars per share)				$ 0.20	$ 0.105
Dividends declared	96,769	67,677	10,097
Dividend paid (in dollars)	$ 96,771	$ 70,122	$ 10,282