Income Taxes (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Taxes [Abstract]
Adjustment of deferred tax balances	$ 23,000,000	$ 7,000,000
Domestic production activities deduction	14,000,000
Federal research and development credits	5,000,000	5,000,000
Tax reserve adjustment	11,000,000
Non-deductible transaction costs	2,000,000	3,000,000
Reversal of reserves for uncertain tax postions		2,000,000	12,000,000
Settlement of 2010 IRS audit		5,000,000
Effect of expiration of statute of limitations during next twelve months	3,000,000
State tax operating loss carryforward	3,000,000,000
Gross tax liability for tax positions that may not be sustained under a more likely than not threshold	20,000,000
Additional interest recognized on tax liability	1,000,000
Accrued interest on tax liability	$ 1,000,000	$ 1,000,000