Summary of Significant Accounting Policies (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Accounting Policies [Abstract]
Unbilled Audit Premiums	$ 12,000,000	$ 7,000,000	$ 1,000,000
Deposit contracts, liabilities	72,000,000	75,000,000
Depreciation	38,000,000	38,000,000	40,000,000
Goodwill and intangible asset impairment	0
Indefinite-lived Intangible Assets [Line Items]
Interest payments	125,000,000	119,000,000	111,000,000
Income taxes paid	186,000,000	133,000,000	48,000,000
Other Assets
Indefinite-lived Intangible Assets [Line Items]
Intangible assets, net (excluding goodwill)	$ 72,000,000	$ 31,000,000