Recent Accounting Changes (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
New Accounting Pronouncements And Changes In Accounting Principles [Abstract]
Health Care Reform Industry Assessment Fee Liability	$ 310		$ 238
Health Care Reform Industry Assessment Fee Expense	$ 80	$ 60