Share-based Compensation - Activity (Details) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Stock options
Options Outstanding
Balance at beginning of year (in shares)	761,686	977,745	1,071,977
Granted (in shares)	0	0	0
Exercised (in shares)	(11,314)	0	0
Lapsed or cancelled (in shares)	(356,283)	(216,059)	(94,232)
Balance at end of period (in shares)	394,089	761,686	977,745
Options exercisable at end of period (in shares)	394,089	760,743	862,593
Weighted Average Exercise Price
Balance at beginning of year (in dollars per share)	$ 105.76	$ 108.57	$ 109.82
Exercised (in dollars per share)	72.30	0	0
Lapsed or cancelled (in dollars per share)	112.56	118.49	122.84
Balance at end of period (in dollars per share)	100.56	105.76	108.57
Options exercisable at end of period (in dollars per share)	$ 100.56	$ 105.76	$ 107.86
Restricted Stock Awards
Summary of restricted stock
Balance at beginning of year (in shares)	3,337,545	3,362,456	3,254,553
Granted (in shares)	141,515	8,693	119,122
Cancelled (in shares)	(19,697)	(33,604)	(11,219)
Balance at end of period (in shares)	3,459,363	3,337,545	3,362,456
Vested during the period (in shares)	122,759	125,064	106,780
Compensation expense recorded	$ 8,497,054	$ 10,895,459	$ 12,892,249