Stock Benefit Plans (Summary Of The Status Of Restricted Stock Unit And Performance Unit Awards) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Restricted Stock Units (RSUs)
Restricted Stock Units and Performance Stock Units [Roll Forward]
Non-vested balance at January 1, 2015 (in shares)	2,097,730
Granted (in shares)	1,737,354
Vested (in shares)	(1,264,076)
Forfeited (in shares)	(111,715)
Non-vested balance at December 31, 2015 (in shares)	2,459,293	2,097,730
Weighted Average Grant Date Fair Value [Roll Forward]
Non-vested balance at January 1, 2015 (in dollars per share)	$ 38.74
Granted (in dollars per share)	56.81	$ 48.16	$ 36.70
Vested (in dollars per share)	35.56
Forfeited (in dollars per share)	52.67
Non-vested balance at December 31, 2015 (in dollars per share)	$ 52.51	$ 38.74
Performance Shares
Restricted Stock Units and Performance Stock Units [Roll Forward]
Non-vested balance at January 1, 2015 (in shares)	868,008
Granted (in shares)	210,829
Vested (in shares)	(373,449)
Forfeited (in shares)	(27,223)
Non-vested balance at December 31, 2015 (in shares)	678,165	868,008
Weighted Average Grant Date Fair Value [Roll Forward]
Non-vested balance at January 1, 2015 (in dollars per share)	$ 37.56
Granted (in dollars per share)	56.84	$ 48.00	$ 36.54
Vested (in dollars per share)	31.99
Forfeited (in dollars per share)	46.91
Non-vested balance at December 31, 2015 (in dollars per share)	$ 46.25	$ 37.56