Capital Stock Capital Stock (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended			5 Months Ended	6 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Jun. 08, 2011 ICG [Member]	Jul. 08, 2011 ICG [Member]	Dec. 31, 2011 ICG [Member]
Stock transactions
Common stock public offering price				$ 27.00
Proceeds from the sale of common stock, net		$ 1,267,933			$ 18,400	$ 1,250,000
Common stock issued				48,000,000		700,000
Stock repurchase authorized number	14,000,000
Outstanding shares available for repurchase	10,925,800