Income Taxes - Narrative (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Operating Loss Carryforwards [Line Items]
Valuation allowance, deferred tax asset, increase (decrease), amount	$ 4.4	$ 5.0
Operating Loss Carryforwards, Excess Tax Benefits From Stock-Based Award Exercises Not Recorded	6.2
Deferred Tax Assets, Operating Loss Carryforwards, Internal Revenue Code Section 382 Limitation	26.4
Research Tax Credit Carryforward [Member]
Operating Loss Carryforwards [Line Items]
Income Tax Credits and Adjustments	1.8
Internal Revenue Service (IRS) [Member]
Operating Loss Carryforwards [Line Items]
Operating Loss Carryforwards	74.6
France [Member] | Other Current Assets [Member]
Operating Loss Carryforwards [Line Items]
International	$ 2.7	$ 1.5