Debt (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended		0 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	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	Sep. 30, 2014 Term Loan
Debt Instrument [Line Items]
Required quarterly payments, percentage of original principal										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	$ 50	$ 4	$ 150	$ 4
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%