Common Stock (Details) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended		6 Months Ended			6 Months Ended	51 Months Ended	57 Months Ended			0 Months Ended
	Apr. 30, 2014	Sep. 30, 2010	Jun. 30, 2014	Jun. 30, 2013	Dec. 31, 2013	Jun. 30, 2014 Approved request	Dec. 31, 2013 Approved request	Jun. 30, 2014 Approved request	Jun. 30, 2014 Common stock	Dec. 31, 2013 Common stock	May 12, 2014 Tender Offer	Apr. 15, 2014 Tender Offer
Class of Stock [Line Items]
Common stock, shares outstanding (in shares)			162,180,226		174,120,408				162,180,226	174,120,408
Shares retired (in shares)											14,200,000
Average price per share (in dollars per share)						$ 10.00	$ 9.63	$ 9.63			$ 10.75	$ 10.75
Payments for Repurchase of Common Stock			$ 154,269	$ 1,330							$ 152,300
Dividends declared (in dollars per share)	$ 0.46	$ 0.605
Dividends declared per day (in dollars per share)		$ 0.0016575342
Number of Requests						1	35	36
Number of Shares Repurchased						5,000	279,594	284,594