Stock Option Summary (Details) - Share-based Payment Arrangement, Option [Member] - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Sep. 30, 2020	Sep. 30, 2019
[Line Items]
Outstanding, beginning balance (in shares)	458	895	458	895
Outstanding, beginning balance, weighted average exercise price per share (in dollars per share)	$ 56.38	$ 47.93	$ 56.38	$ 47.93
Outstanding, weighted average remaining contractual life	7 years	6 years 2 months 12 days	7 years	5 years 6 months
Outstanding, beginning balance, aggregate intrinsic value	$ 12,641	$ 4,806	$ 12,641	$ 4,806
Granted (in shares)			80	76
Granted, weighted average exercise price (in dollars per share)			$ 84.38	$ 76.55
Granted, weighted average grant date fair value			$ 26.21	$ 26.20
Exercised (in shares)			(49)	(117)
Exercised, weighted average exercise price (in dollars per share)			$ 50.90	$ 40.10
Exercised, aggregate intrinsic value			$ 1,189	$ 2,745
Forfeited (in share)			(5)	(8)
Forfeited, weighted average grant date fair value (in dollars per share)			$ 83.80	$ 67.38
Expired (in shares)				(11)
Expired weighted average exercise price (in dollars per share)				$ 66.24
Outstanding, ending balance (in shares)			484	835
Outstanding, ending balance, weighted average exercise price per share (in dollars per share)			$ 61.30	$ 51.22
Outstanding, weighted average remaining contractual life	7 years	6 years 2 months 12 days	7 years	5 years 6 months
Outstanding, ending balance, aggregate intrinsic value			$ 3,816	$ 19,190
Exercisable (in shares)			319
Exercisable, weighted average exercise price (in dollars per share)			$ 52.68
Exercisable, weighted average remaining contractual term			6 years
Exercisable, aggregate intrinsic value			$ 3,764