Debt (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended		0 Months Ended
	Dec. 31, 2013	Dec. 31, 2013 Credit Facilities	Oct. 11, 2013 Credit Facilities Prime Rate Base Rate Loans	Oct. 11, 2013 Credit Facilities Federal Funds Effective Rate Base Rate Loans	Oct. 11, 2013 Credit Facilities LIBOR Rate Base Rate Loans	Oct. 11, 2013 Credit Facilities LIBOR Rate LIBOR Rate Loans	Oct. 11, 2013 Term Loan	Dec. 31, 2013 Term Loan
Debt Instrument [Line Items]
Percentage of required quarterly payments								0.25%
LIBOR floor rate							0.75%
Variable rate at end of period		3.25%
Applicable margin (as a percent)				0.50%	1.00%
Interest expense	$ 57
Description of variable rate basis			Prime rate as designated by the administrative agent	Federal funds rate	LIBOR rate for one month	LIBOR
Percentage of consolidated total assets pledged as collateral		70.00%