Significant Accounting Policies (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Warranty Costs
Warranty period	1 year
Advertising Expense
Advertising expenses	$ 0.6	$ 0.5	$ 0.8
Concentration of Credit Risk
Allowance for doubtful accounts	$ 0.7	$ 2.4
Maturity period of irrevocable letters of credit, minimum	0 days
Maturity period of irrevocable letters of credit, maximum	90 days
Cash, Cash Equivalents, and Short-Term Investments
Maturity period of short-term investments, minimum	3 months
Cash and cash equivalents maintained outside the U.S. by subsidiaries (as a percent)	81.00%	71.00%
Maximum
Long-Lived Intangible Assets
Estimated useful lives	17 years