Equity-Based Awards, Phantom Unit Awards (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2015		Dec. 31, 2014		Dec. 31, 2013
Summary of awards activity, equity instruments other than options, additional disclosures [Abstract]
Cash payments made in connection with DERs		$ 7.7		$ 3.7		$ 0.0
Phantom Unit Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rate of phantom unit awards (in hundredths)		25.00%
Summary of awards activity, equity instruments other than options [Roll Forward]
Beginning of period (in units)		3,342,390		0
Granted (in units)		3,496,140	[1]	3,530,710	[2]
Vested (in units)		(940,415)		(38,200)
Forfeited (in units)		(471,166)		(150,120)
End of period (in units)		5,426,949		3,342,390		0
Common units issued in connection with the vesting of phantom unit awards (in units)		618,395		23,311
Phantom units outstanding, weighted-average grant date fair value [Roll Forward]
Weighted-average grant date fair value per unit, at beginning of period (in dollars per unit)	[3]	$ 33.13		$ 0
Granted weighted-average grant date fair value per unit (in dollars per unit)	[3]	33.96	[1]	33.12	[2]
Vested weighted-average grant date fair value per unit (in dollars per unit)	[3]	33.14		33.04
Forfeited weighted-average grant date fair value per unit (in dollars per unit)	[3]	33.51		33.12
Weighted-average grant date fair value per unit, at end of period (in dollars per unit)	[3]	$ 33.63		$ 33.13		$ 0
Summary of awards activity, equity instruments other than options, additional disclosures [Abstract]
Aggregate grant date fair value		$ 118.7		$ 117.0
Estimated forfeiture rate (in hundredths)		3.50%		3.40%
Cash payments made in connection with DERs		$ 7.7		$ 3.7		$ 0.0
Total intrinsic value of phantom unit awards that vested during period		31.2		$ 1.4		$ 0.0
Unrecognized Compensation Expense [Abstract]
Unrecognized compensation cost		$ 77.0
Recognition period for total unrecognized compensation cost		2 years
Phantom Unit Awards [Member] | Minimum [Member]
Summary of awards activity, equity instruments other than options, additional disclosures [Abstract]
Grant date market price of common units (in dollars per unit)		$ 27.31		$ 33.04
Phantom Unit Awards [Member] | Maximum [Member]
Summary of awards activity, equity instruments other than options, additional disclosures [Abstract]
Grant date market price of common units (in dollars per unit)		$ 34.40		$ 37.59
Phantom Unit Awards [Member] | Enterprise [Member]
Unrecognized Compensation Expense [Abstract]
Unrecognized compensation cost		$ 69.2

[1] The aggregate grant date fair value of phantom unit awards issued during 2015 was $118.7 million based on a grant date market price of our common units ranging from $27.31 to $34.40 per unit. An estimated annual forfeiture rate of 3.5% was applied to these awards.

[2] The aggregate grant date fair value of phantom unit awards issued during 2014 was $117.0 million based on a grant date market price of our common units ranging from $33.04 to $37.59 per unit. An estimated annual forfeiture rate of 3.4% was applied to these awards.

[3] Determined by dividing the aggregate grant date fair value of awards (before an allowance for forfeitures) by the number of awards issued.