UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares	Mar. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Series A preferred unitholders, issued	300,000	300,000
Series A preferred unitholders, outstanding	300,000	300,000
Common limited partner capital (in shares), issued	82,695,311	73,390,853
Common limited partner capital (in shares), outstanding	82,695,311	73,390,853
General partner interests (in shares), issued	0	1,490,999
General partner interests (in shares), outstanding	0	1,490,999