Share-Based Compensation (Summary Of All RSU MSPs Granted To Employees And Non-Employee Directors) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
RSU outstanding at end of period, RSUs			381,561
RSU MSPs [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
RSU outstanding at beginning of period, RSUs	72,113
Granted, RSUs	56,379	34,937
Settled, RSUs	(16,866)
Cancelled, RSUs	(5,024)
RSU outstanding at end of period, RSUs	72,113	72,113	106,602
RSU exercisable at end of period, RSUs		7,972,000	5,446,000
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
RSU outstanding at beginning of period, Weighted Average Price	$ 32.25
Granted, Weighted Average Price			$ 22.53
Settled, Weighted Average Price			28.81
Cancelled, Weighted Average Price			26.34
RSU outstanding at end of period, Weighted Average Price	$ 28.06	$ 32.25
RSU exercisable at end of period, Weighted Average Price			$ 31.90