Income Taxes (Details Textual) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes (Textual) [Abstract]
Valuation allowance	$ 427,000,000	$ 349,000,000
Deferred tax liability	8,000,000
Excess of financial reporting over the tax basis of investments not reinvested	65,000,000
Excess of financial reporting over the tax basis of investments to be reinvested	1,900,000,000
Total income tax provision	84,000,000	70,000,000	91,000,000
Effective income tax rate	19.80%	23.50%	23.40%
Unrecognized tax benefits	44,000,000	30,000,000	8,000,000	5,000,000
Interest accrued for unrecognized tax benefits	1,000,000
ITT [Member]
Income Taxes (Textual) [Abstract]
Income Taxes, Amount Owed to Related Party, Pursuant to Agreement	$ 7,000,000