Income Taxes - Unrecognized Tax Benefits (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Balance at beginning of period	$ 0	$ 0	$ 23,000,000
Additions for tax positions related to prior years	0	0	4,500,000
Reductions for tax positions related to prior years	0	0	(4,500,000)
Reductions for settlements with taxing authorities	0	0	(23,000,000)
Balance at end of period	0	0	0
Accrued interest and penalties related to unrecognized tax benefits	$ 0