Equity - Schedule of Stock Options, SARS, and Non-vested Restricted Stock (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock Options and SARs
Outstanding, end of year (in shares)	116,417
Exercisable at end of year (in shares)				66,602
Non-vested Restricted Stock
Outstanding, beginning of year (in shares)	62,597	80,153	95,015
Granted (in shares)	53,471	41,735	32,070
Canceled (in shares)	(4,042)	(17,054)	(1,098)
Vested and issued (in shares)	(28,070)	(42,237)	(45,834)
Outstanding, end of year (in shares)	83,956	62,597	80,153
Weighted- Average Grant Date Fair Value
Outstanding, beginning of year (in dollars per share)	$ 75.81	$ 60.98	$ 44.39
Granted (in dollars per share)	66.02	80.51	84.03
Canceled (in dollars per share)	69.66	74.97	86.15
Vested and issued (in dollars per share)	70.13	52.65	42.12
Outstanding, end of year (in dollars per share)	$ 75.81	$ 60.98	$ 44.39	$ 71.76	$ 75.81	$ 60.98
SARs
Stock Options and SARs
Outstanding, beginning of year (in shares)	98,836	124,960	163,272
Granted (in shares)	34,881	24,582	10,122
Exercised (in shares)	(15,912)	(40,851)	(48,434)
Canceled (in shares)	(1,388)	(9,855)	0
Outstanding, end of year (in shares)	116,417	98,836	124,960
Exercisable at end of year (in shares)				66,602	72,696	95,675
Weighted- Average Exercise Price
Outstanding, beginning of year (in dollars per share)	$ 46.47	$ 38.38	$ 32.95
Granted (in dollars per share)	74.80	82.76	86.15
Exercised (in dollars per share)	26.93	35.61	30.06
Canceled (in dollars per share)	86.15	79.45	0
Outstanding, end of year (in dollars per share)	$ 57.16	$ 46.47	$ 38.38
Exercisable at end of year				$ 42.08	$ 34.07	$ 31.41