Shareholders' Equity (Tables)

12 Months Ended

Dec. 31, 2021

Stockholders' Equity Note [Abstract]

Summary of the components of accumulated other comprehensive income (loss), net of tax

The following is a summary of the components of accumulated other comprehensive income (loss), net of tax (in millions):

	Foreign Currency Translation			Derivatives Designated As Hedging Instruments			Pension Liability Adjustment			Accumulated Other Comprehensive Income (Loss)
Balance at December 31, 2018	$	46.9		$	—		$	(29.9	)	$	17.0
Other comprehensive income (loss)		(3.8	)		(15.7	)		(25.1	)		(44.6	)
Realized gain on reclassification		—			—			2.1			2.1
Balance at December 31, 2019		43.1			(15.7	)		(52.9	)		(25.5	)
Other comprehensive income (loss)		97.8			(75.8	)		2.3			24.3
Realized gain on reclassification		—			—			4.9			4.9
Balance at December 31, 2020		140.9			(91.5	)		(45.7	)		3.7
Other comprehensive income (loss)		(77.8	)		51.4			11.6			(14.8	)
Realized gain on reclassification		—			—			2.9			2.9
Balance at December 31, 2021	$	63.1		$	(40.1	)	$	(31.2	)	$	(8.2	)

Schedule of the impact of stock-based compensation expense

The following presents the impact of stock-based compensation expense on our consolidated statements of income (in millions):

	2021		2020		2019
Stock options	$	1.3	$	1.8	$	2.7
Restricted stock awards		—		—		0.3
Restricted stock units		13.2		11.5		8.9
Total stock-based compensation	$	14.5	$	13.3	$	11.9

	2021		2020		2019
Cost of product revenue	$	2.2	$	2.0	$	1.8
Selling, general and administrative		10.1		9.3		8.3
Research and development		2.2		2.0		1.8
Total stock-based compensation	$	14.5	$	13.3	$	11.9

Schedule of stock option activity

Stock option activity for the year ended December 31, 2021 is as follows:

	Number of Options			Weighted- Average Price Per Share		Weighted - Average Remaining Contractual Term (in Years)		Aggregate Intrinsic Value (in millions) (a)
Outstanding at December 31, 2020		1,856,176		$	25.32		4.2	$	53.5
Granted		79,632			85.10
Exercised		(580,656	)		20.31
Forfeited/Expired		—			—
Outstanding at December 31, 2021		1,355,152		$	30.98		4.1	$	71.9
Exercisable at December 31, 2021		1,093,488		$	24.96		3.6	$	64.5
Exercisable and expected to vest at December 31, 2021 (b)		1,326,095		$	30.32		4.0	$	71.2

(a) Represents the number of vested options at December 31, 2021, plus the number of unvested options at December 31, 2021 that are ultimately expected to vest based on our estimated forfeiture rate.

(b) The aggregate intrinsic value is calculated as the positive difference between the exercise price of the underlying options and the quoted price of our common stock on December 31, 2021.

Schedule of Unvested restricted stock unit activity

Restricted stock unit activity is presented below:

	Shares Subject to Restriction			Weighted- Average Grant Date Fair Value Per Share
Outstanding at December 31, 2020		805,052		$	39.63
Granted		218,223			78.03
Vested		(336,310	)		37.26
Forfeited		(32,495	)		43.90
Outstanding at December 31, 2021		654,470		$	53.44