Employee Benefits - Summary of Equity-Based Awards for Employees (Details) - $ / shares	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Awards
Share-based awards granted (in shares)	39,000	200,000	39,000	200,000
Common Stock Awards
Awards
Nonvested common stock awards, Beginning balance (in shares)			231,280
Granted (in shares)			48,673
Vested (in shares)			(83,403)
Forfeited/Cancelled (in shares)			(1,092)
Nonvested common stock awards, Ending balance (in shares)	195,458		195,458
Weighted Average Grant Date Fair Value Per Share
Nonvested performance-based stock awards, Beginning balance (in USD per share)			$ 48.05
Granted (in USD per share)			125.75
Vested (in USD per share)			48.63
Forfeited/Cancelled (in USD per share)			43.73
Nonvested performance-based stock awards, Ending balance (in USD per share)	$ 67.17		$ 67.17
Performance-Based Stock Awards
Awards
Nonvested performance-based stock awards/units, Beginning balance (in shares)			166,961
Share-based awards granted (in shares)			42,449
Vested (in shares)			(64,525)
Forfeited/Cancelled (in shares)			0
Nonvested performance-based stock awards/units, Ending balance (in shares)	144,885		144,885
Weighted Average Grant Date Fair Value Per Share
Nonvested performance-based stock awards/units, Beginning balance (in USD per share)			$ 59.97
Granted (in USD per share)			123.32
Vested (in USD per share)			52.79
Forfeited/Cancelled (in USD per share)			0
Nonvested performance-based stock awards/units, Ending balance (in USD per share)	$ 81.73		$ 81.73
Performance-Based Restricted Stock Units
Awards
Nonvested performance-based stock awards/units, Beginning balance (in shares)			13,273
Share-based awards granted (in shares)			8,470
Vested (in shares)			(12,952)
Forfeited/Cancelled (in shares)			(443)
Nonvested performance-based stock awards/units, Ending balance (in shares)	8,348		8,348
Weighted Average Grant Date Fair Value Per Share
Nonvested performance-based stock awards/units, Beginning balance (in USD per share)			$ 36.51
Granted (in USD per share)			126.89
Vested (in USD per share)			36.51
Forfeited/Cancelled (in USD per share)			61.40
Nonvested performance-based stock awards/units, Ending balance (in USD per share)	$ 126.89		$ 126.89