Partners' Capital, Mezzanine and Equity Distributions (Change in Class A Convertible Preferred Units) (Details) - USD ($) $ in Thousands		12 Months Ended
	Sep. 01, 2017	Dec. 31, 2017
Carrying Amount
Beginning Balance		$ 0
Ending Balance		$ 697,151
Units
Beginning Balance (in shares)		0
Issuance of Preferred Units (in shares)		22,249,494
Distribution paid-in-kind (in shares)		162,234
Ending Balance (in shares)		22,411,728
Class A Convertible Preferred Stock Units [Member]
Carrying Amount
Beginning Balance		$ 0
Issuance of Preferred Units, net	$ 726,419	726,419
Allocation to Preferred Distribution Rate Reset Election		(34,450)
Distribution paid-in-kind		5,469
Allocation of Distribution paid-kind to Preferred Distribution Rate Reset Election		(287)
Ending Balance	$ 726,419	$ 697,151
Units
Distribution paid-in-kind (in shares)		162,234