Accounting for Stock-based Compensation - Summary of Performance Shares Activity (Details) - Performance Shares - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended				24 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020
Number of Shares
Number of Shares, Non-vested Beginning Balance	142,121	148,414	169,486		169,486
Number of Shares, Granted	54,216	87,314	85,928	63,258	85,540
Number of Shares, Vested	(63,258)	(88,038)	(107,000)
Number of Shares, Cancelled		(5,569)
Number of Shares, Non-vested Ending Balance	133,079	142,121	148,414	169,486	142,121
Number of Shares, expected to vest in the future	85,540
Weighted-Average Grant Date Fair Value
Weighted-Average Grant Date Fair Value, Non-vested Beginning Balance	$ 68.19	$ 60.67	$ 45.15		$ 45.15
Weighted-Average Grant Date Fair Value, Granted	85.03	51.44	62.07
Weighted-Average Grant Date Fair Value, Vested	65.05	38.81	37.21
Weighted-Average Grant Date Fair Value, Cancelled		69.66
Weighted-Average Grant Date Fair Value, Non-vested Ending Balance	76.54	$ 68.19	$ 60.67	$ 45.15	$ 68.19
Weighted-Average Grant Date Fair Value, expected to vest in the future	$ 73.38
Aggregate Intrinsic Value
Aggregate Intrinsic Value, Non-vested	$ 13,647,251
Aggregate Intrinsic Value, expected to vest in the future	$ 8,772,127