Income Taxes (Narrative) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2015	Dec. 31, 2014
Income Tax Contingency [Line Items]
Gross unrecognized tax benefits	$ 32.9	$ 32.9
Accrued interest and penalties on unrecognized tax benefits	17.3	$ 17.3
Possible decrease in unrecognized tax benefits	$ 14.7
Minimum
Income Tax Contingency [Line Items]
Income tax years under examination	2004
Maximum
Income Tax Contingency [Line Items]
Income tax years under examination	2015