Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule of Stock Options Roll Forward

A summary of award activity by type for the three months ended March 31, 2017 is presented below.

Stock Options	Awards/Units (in millions)		Weighted- Average Exercise Price		Aggregate Intrinsic Value  (in millions)		Weighted Average Remaining Contractual Life (years)
Outstanding at January 1, 2017	9.6		$	14.40
Granted	0.9		$	29.48
Exercised	(0.9	)	$	10.09
Forfeited	(0.1	)	$	23.38
Outstanding at March 31, 2017	9.5		$	16.08
Vested and expected to vest at March 31, 2017	9.5		$	16.08	$	153.7	7.12
Exercisable at March 31, 2017	7.2		$	12.21	$	144.8	6.53

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]

Restricted Stock Awards and Restricted Stock Units	Awards (millions)		Weighted-Average Fair Value
Outstanding at January 1, 2017	2.3		$	29.18
Granted	0.6		29.48
Vested	(0.3	)	23.36
Forfeited	—		—
Outstanding at March 31, 2017	2.6		$	29.86

Schedule of Share-based Compensation Arrangement by Share-based Payment Award, Performance-Based Units, Vested and Expected to Vest [Table Text Block]

Performance Stock Awards and Performance Share Units	Awards (millions)	Weighted-Average Fair Value
Outstanding at January 1, 2017	0.3	$	27.74
Granted	0.3	38.11
Vested	—	—
Forfeited	—	—
Outstanding at March 31, 2017	0.6	$	31.08