Equity Compensation Plans - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
	Jan. 15, 2020	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Proceeds from stock options exercised		$ 19.2	$ 11.6
Nonqualified stock options contractual term (in years)		10 years
Vesting period		4 years
Exercisable, contractual term		6 years 3 months 14 days
Outstanding, contractual term		4 years 6 months 10 days
Total unrecognized compensation cost related to nonvested share-based compensation arrangements		$ 117.3
Unrecognized compensation cost weighted average period (in years)		2 years 11 months 8 days
Grant date fair value options		$ 5.6	4.4
Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted stock (in shares)	148,658
Grant date fair value restricted stock vested		$ 6.1	4.7
Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Number of shares per award		1
Target levels		100.00%
Grant date fair value restricted stock vested		$ 2.1	$ 0.5
Employee stock purchase plan | UK Sharesave Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved and available for future issuance (in shares)		462,040
Vesting period		3 years
Share-based compensation arrangement by share-based payment award, discount from market price, purchase date		5.00%
Employee stock purchase plan | US ESPP
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved and available for future issuance (in shares)		1,283,317
Shares issued in period (in shares)		9,451	8,310
Common stock issued, discounted price (in dollars per share)		$ 132.41	$ 126.35
Minimum | Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target levels		0.00%
Maximum | Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Target levels		200.00%
2013 Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock reserved and available for future issuance (in shares)		3,075,647
Tranche 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Granted stock (in shares)	882,749
Tranche 1 | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Granted stock (in shares)	141,725
Tranche 2 | Restricted stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	4 years
Granted stock (in shares)	6,933
Tranche 3 | Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Granted stock (in shares)	50,736