Equity (Performance Share and Restricted Stock Unit) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2017	Aug. 07, 2017	Aug. 04, 2017
Summary of Weighted Average Grant Date Fair Value
Share Price		$ 48.17	$ 53.92
Performance Shares
Summary of performance share activity
Shares Outstanding at January 1,	3,817,100
Granted Shares	1,225,333
Forfeited Shares	(270,292)
Paid	(1,192,734)
Other Separation adjustment	454,353
Shares Outstanding at December 31,	4,033,760
Vested and expected to vest at December 31,	3,971,002
Summary of Weighted Average Grant Date Fair Value
Weighted Average Grant Date Fair Value Outstanding January 1,	$ 49.88
Granted Weighted Average Grant Date Fair Value	45.60
Forfeited Weighted Average Grant Date Fair Value	42.94
Payable Weighted Average Grant Date Fair Value	44.84
Other Separation adjustment	42.34
Weighted Average Grant Date Fair Value Outstanding December 31,	46.02
Weighted Average Grant Date Fair Value Share expected to vest at December 31,	$ 46.02
Restricted Stock Units
Summary of performance share activity
Shares Outstanding at January 1,	3,422,013
Granted Shares	1,445,238
Forfeited Shares	(251,216)
Paid	(1,720,168)
Other Separation adjustment	408,510
Shares Outstanding at December 31,	3,304,377
Vested and expected to vest at December 31,	3,246,476
Summary of Weighted Average Grant Date Fair Value
Weighted Average Grant Date Fair Value Outstanding January 1,	$ 39.08
Granted Weighted Average Grant Date Fair Value	42.45
Forfeited Weighted Average Grant Date Fair Value	35.64
Payable Weighted Average Grant Date Fair Value	36.81
Other Separation adjustment	37.07
Weighted Average Grant Date Fair Value Outstanding December 31,	37.17
Weighted Average Grant Date Fair Value Share expected to vest at December 31,	$ 37.14