Equity (Details Textual) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Feb. 28, 2011
Equity (Textual)
Preferred stock, shares authorized	8,000,000	8,000,000
Common stock shares authorized for repurchase	4,200,000			20,000,000
Repurchase of common stock, shares	2,000,000	7,800,000
Repurchase of common stock, value	$ 400,309	$ 984,715	$ 497,975