Unaudited Condensed Consolidated Balance Sheets (Parenthetical) - shares shares in Thousands	Mar. 31, 2019	Dec. 31, 2018
Common Units
Capital units, Outstanding	80,939	80,844
Subordinated Units
Capital units, Outstanding	64,955	64,955

Number of common units of ownership outstanding of a limited liability company (LLC).

No definition available.

Name:	us-gaap_CommonUnitOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant