Stock-Based Compensation (Stock Option Activity) (Details) - Stock Options - $ / shares	1 Months Ended	9 Months Ended
	Apr. 30, 2016	Sep. 30, 2016
Number of Shares
Options outstanding at the beginning of the period (in shares)		3,630,000
Options granted (in shares)		716,000
Options exercised (in shares)		(344,000)
Options forfeited (in shares)		(24,000)
Options expired (in shares)		(42,000)
Options outstanding at the end of the period (in shares)		3,936,000
Exercisable at the end of the period (in shares)		2,783,000
Vested and expected to vest at the end of the period (in shares)		3,840,000
Weighted-Average Exercise Price
Options outstanding at the beginning of the period (in dollars per share)		$ 23.80
Options granted (in dollars per share)		26.98
Options exercised (in dollars per share)		18.58
Options forfeited (in dollars per share)		29.42
Options expired (in dollars per share)		28.70
Options outstanding at the end of the period (in dollars per share)		24.75
Exercisable at the end of the period (in dollars per share)		23.19
Vested and expected to vest at the end of the period (in dollars per share)		$ 24.66
Performance-Based Vesting
Number of Shares
Options granted (in shares)	75,531	76,000
Options outstanding at the end of the period (in shares)		76,000
Vested and expected to vest at the end of the period (in shares)		72,000
Weighted-Average Exercise Price
Options granted (in dollars per share)	$ 31.12	$ 31.12
Options outstanding at the end of the period (in dollars per share)		31.12
Vested and expected to vest at the end of the period (in dollars per share)		$ 31.12