Stock Compensation - Option Activity (Details) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2020 USD ($) $ / shares shares
Number of Shares
Outstanding, beginning number of shares (in shares) | shares	2,913,272
Exercised (in shares) | shares	(956,258)
Canceled or expired, number of shares (in shares) | shares	(52,265)
Outstanding, ending number of shares (in shares) | shares	1,904,749
Weighted-average Exercise Price
Outstanding, beginning of year, weighted-average exercise price (in dollars per share) | $ / shares	$ 40.10
Exercised, weighted-average exercise price (in dollars per share) | $ / shares	39.07
Canceled or expired, weighted-average exercise price (in dollars per share) | $ / shares	43.27
Outstanding - end of year, weighted-average exercise price (in dollars per share) | $ / shares	$ 40.53
Outstanding - end of year, weighted-average remaining contractual term (in years)	7 years
Outstanding - end of year, aggregate intrinsic value | $	$ 70.1
Option expected to vest, number of shares (in shares) | shares	1,904,749
Option expected to vest, weighed-average exercise price (in dollars per share) | $ / shares	$ 40.53
Option expected to vest, weighted-average remaining contractual term (in years)	7 years
Option expected to vest, aggregate intrinsic value | $	$ 70.1
Options exercisable, number of shares (In shares) | shares	1,259,075
Options exercisable, weighted-average exercise price (in dollars per share) | $ / shares	$ 38.94
Options exercisable, weighted-average remaining contractual term (in years)	6 years
Options exercisable, aggregate intrinsic value | $	$ 48.4