Fair Value Election and Measurement Level 3 Significant Unobservable Input Assumptions (Additional Information) (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2015		Dec. 31, 2014
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Other Liabilities, Fair Value Disclosure	$ 21	[1]	$ 27	[1]

[1] Includes contingent consideration obligations related to acquisitions.