Stock Benefit Plans (Summary Of The Status Of Restricted Stock Unit And Performance Unit Awards) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Restricted Stock Units (RSUs)
Restricted Stock Units and Performance Stock Units [Roll Forward]
Non-vested balance at January 1, 2016 (in shares)	2,459,293
Granted (in shares)	1,844,661
Vested (in shares)	(1,100,706)
Forfeited (in shares)	(159,219)
Non-vested balance at December 31, 2016 (in shares)	3,044,029	2,459,293
Weighted Average Grant Date Fair Value [Roll Forward]
Non-vested balance at January 1, 2016 (in dollars per share)	$ 52.51
Granted (in dollars per share)	57.54	$ 56.81	$ 48.16
Vested (in dollars per share)	49.62
Forfeited (in dollars per share)	56.41
Non-vested balance at December 31, 2016 (in dollars per share)	$ 56.40	$ 52.51
Performance Shares
Restricted Stock Units and Performance Stock Units [Roll Forward]
Non-vested balance at January 1, 2016 (in shares)	678,165
Granted (in shares)	323,990
Vested (in shares)	(260,089)
Forfeited (in shares)	(20,049)
Non-vested balance at December 31, 2016 (in shares)	722,017	678,165
Weighted Average Grant Date Fair Value [Roll Forward]
Non-vested balance at January 1, 2016 (in dollars per share)	$ 46.25
Granted (in dollars per share)	57.47	$ 57.33	$ 48.00
Vested (in dollars per share)	36.56
Forfeited (in dollars per share)	54.49
Non-vested balance at December 31, 2016 (in dollars per share)	$ 54.68	$ 46.25