Summary of Significant Accounting Policies - Stock-Based Compensation (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Stock-Based Compensation
Total stock-based compensation	$ 11.9	$ 11.3	$ 11.0
Estimated forfeiture rate (as a percent)	8.30%	7.50%	6.70%
Cost of revenues
Stock-Based Compensation
Total stock-based compensation	$ 1.8	$ 1.7	$ 1.7
Selling, general and administrative
Stock-Based Compensation
Total stock-based compensation	8.3	7.9	7.6
Research and development
Stock-Based Compensation
Total stock-based compensation	1.8	1.7	1.7
Stock options
Stock-Based Compensation
Total stock-based compensation	$ 2.7	$ 4.2	$ 6.2
Risk-free interest rates (as a percent)	1.55%	2.80%
Risk-free interest rates, minimum (as a percent)			1.78%
Risk-free interest rates, maximum (as a percent)			2.09%
Expected life	5 years 3 months 29 days	5 years 4 months 17 days	5 years 6 months 22 days
Volatility (as a percent)	29.57%	28.46%
Volatility, minimum (as a percent)			30.78%
Volatility, maximum (as a percent)			34.13%
Expected dividend yield (as a percent)	0.38%	0.47%
Stock options | Minimum
Stock-Based Compensation
Vesting period	3 years
Expected dividend yield (as a percent)			0.55%
Stock options | Maximum
Stock-Based Compensation
Vesting period	4 years
Expected dividend yield (as a percent)			0.74%
Restricted stock awards
Stock-Based Compensation
Total stock-based compensation	$ 0.3	$ 0.8	$ 1.4
Restricted stock units
Stock-Based Compensation
Total stock-based compensation	8.9	6.3	$ 3.4
Mestrelab Research, S.L
Stock-Based Compensation
Total stock-based compensation	$ 2.3	$ 0.5