Partners' Equity - Preferred Units (Details) - USD ($) $ / shares in Units, $ in Millions						6 Months Ended
	Jul. 01, 2014	Jun. 17, 2014	Jun. 04, 2014	May. 12, 2014	Apr. 17, 2014	Jun. 30, 2015
Class of Stock [Line Items]
Liquidation preference (in dollars per share)						$ 25
WPX acquisition
Class of Stock [Line Items]
Equity interests issuable (in shares)			300,000
Conversion terms, minimum distribution per share			$ 0.90
WPX acquisition | Immediate vesting
Class of Stock [Line Items]
Equity interests issuable (in shares)			100,000
WPX acquisition | Ratable vesting
Class of Stock [Line Items]
Equity interests issuable (in shares)			10,000
Additional cash consideration			$ 35.5
WPX acquisition | Forfeiture, first two anniversaries
Class of Stock [Line Items]
Equity interests forfeiture (in shares)			66,666
WPX acquisition | Forfeiture, third anniversary
Class of Stock [Line Items]
Equity interests forfeiture (in shares)			66,668
Series A Preferred Equity
Class of Stock [Line Items]
Stock issuance (in shares)					2,000,000
Share price					$ 25
Dividend rate						8.00%
Additional shares of underwriter purchase option				300,000
Series A Preferred Equity | three-month LIBOR
Class of Stock [Line Items]
Variable dividend rate						5.24%
Series B Preferred Equity
Class of Stock [Line Items]
Stock issuance (in shares)		7,000,000
Share price		$ 25
Series B Preferred Equity | three-month LIBOR
Class of Stock [Line Items]
Variable dividend rate						5.256%
Series B Preferred Equity | Over-Allotment Option
Class of Stock [Line Items]
Stock issuance (in shares)	200,000
Unvested IDUs [Member] | WPX acquisition
Class of Stock [Line Items]
Equity interests issuable (in shares)			200,000