General - Stock Compensation - Nonvested - Activity (Details)	9 Months Ended
	Sep. 30, 2021 $ / shares shares
Restricted Stock Awards
Shares
Outstanding, beginning of period (in shares) | shares	54,314
Awarded (in shares) | shares	6,312
Outstanding, end of period (in shares) | shares	60,626
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 77.33
Awarded (in dollars per share) | $ / shares	94.56
Outstanding, end of period (in dollars per share) | $ / shares	$ 79.13
Restricted Stock Units (RSUs)
Shares
Outstanding, beginning of period (in shares) | shares	428,362
Awarded (in shares) | shares	280,374
Vested (in shares) | shares	(160,092)
Forfeited (in shares) | shares	(18,188)
Outstanding, end of period (in shares) | shares	530,456
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 65.83
Awarded (in dollars per share) | $ / shares	92.87
Vested (in dollars per share) | $ / shares	68.04
Forfeited (in dollars per share) | $ / shares	75.62
Outstanding, end of period (in dollars per share) | $ / shares	$ 79.12
Performance Based Restricted Stock Units ("PSUs")
Shares
Outstanding, beginning of period (in shares) | shares	278,945
Forfeited (in shares) | shares	(63,324)
Outstanding, end of period (in shares) | shares	215,621
Weighted Average Grant Date Fair Value
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 99.80
Forfeited (in dollars per share) | $ / shares	141.61
Outstanding, end of period (in dollars per share) | $ / shares	$ 87.51