Debt - Term Loans Narrative (Details) (USD $)			3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Dec. 31, 2012 Term Loan [Member]	Nov. 07, 2012 Term Loan [Member]	Mar. 31, 2014 Senior Notes	Dec. 31, 2013 Senior Notes	Apr. 24, 2014 Senior Notes
Long-Term Debt Instrument [Line Items]
Credit Facility Commitment Period			five-year
Unsecured Debt				$ 2,000,000,000
Net proceeds from issuance of unsecured loan			1,935,000,000
Long-term Debt, Gross	12,969,000,000	12,886,000,000					3,000,000,000
Debt Instrument, Unamortized Discount					$ 284,000,000	$ 303,000,000