Stock Incentive Plan (Schedule of Share-based Compensation, Unearned Compensation Related to RSU's) (Details) - Restricted Stock Units (RSUs) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Changes In Unearned Compensation [Roll Forward]
Unearned compensation at beginning of year	$ 132,310	$ 128,390	$ 129,669
RSUs granted, net of cancellations	56,711	54,270	53,583
RSUs expensed	46,441	(47,108)	(47,329)
RSUs forfeitures	7,045	(3,242)	(7,533)
Unearned compensation at end of year	$ 135,535	$ 132,310	$ 128,390