Stock Compensation Plans and Other Employee Benefit Plans (Summary of Plans' Restricted and Performance Share Award Activity) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Restricted Shares
Common Shares
Outstanding, beginning of the period (in shares)	476,813	234,794	144,328
Granted (in shares)	225,680	276,311	117,571
Vested and issued (in shares)	(68,541)	(19,673)	(20,441)
Forfeited or canceled (in shares)	(23,797)	(14,619)	(6,664)
Outstanding, end of the period (in shares)	610,155	476,813	234,794
Vested, but deferred (in shares)	96,920	95,465	93,969
Weighted Average Grant-Date Fair Value
Beginning weighted average grant-date fair value (usd per share)	$ 61.33	$ 59.02	$ 60.37
Weighted average grant-date fair value, granted (usd per share)	95.93	63.96	60.85
Weighted average grant-date fair value, vested and issued (usd per share)	64.49	68.92	74.42
Weighted average grant-date fair value, expired, canceled or forfeited (usd per share)	75.84	63.66	73.54
Ending weighted average grant-date fair value (usd per share)	73.21	61.33	59.02
Weighted average grant-date fair value, vested, but deferred (usd per share)	$ 53.08	$ 52.52	$ 52.11
Performance Shares
Common Shares
Outstanding, beginning of the period (in shares)	557,255	482,608	465,515
Granted (in shares)	160,598	208,851	170,032
Added by performance factor at vesting (in shares)	0	0	48,831
Vested and issued (in shares)	0	0	(180,789)
Forfeited or canceled (in shares)	(172,474)	(134,204)	(20,981)
Outstanding, end of the period (in shares)	545,379	557,255	482,608
Vested, but deferred (in shares)	35,696	35,160	34,609
Weighted Average Grant-Date Fair Value
Beginning weighted average grant-date fair value (usd per share)	$ 62.94	$ 71.15	$ 74.37
Weighted average grant-date fair value, granted (usd per share)	97.14	58.99	63.61
Weighted average grant-date fair value, added by performance factor at vesting (usd per share)	0	0	72.59
Weighted average grant-date fair value, vested and issued (usd per share)	0	0	72.59
Weighted average grant-date fair value, expired, canceled or forfeited (usd per share)	71.52	86.30	72.46
Ending weighted average grant-date fair value (usd per share)	70.30	62.94	71.15
Weighted average grant-date fair value, vested, but deferred (usd per share)	$ 44.38	$ 43.69	$ 43.14