Equity (Receivable) (Details) - Notes receivable from unit-holders - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 05, 2017	Mar. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Notes receivable from unit-holders
Unit price (in dollars per unit)		$ 100	$ 100
Receivable interest rate (as a percent)		6.00%	6.00%
Units issued (in units)		19,508	19,508
Units issued during period (in units)			0	0
Proceeds from collection of notes receivable	$ 1,259	$ 2,700
Proceeds from collection of interest receivable		$ 315
Previously assigned units	19,508	27,368	27,368
Receivable from unit-holders		$ 1,951	$ 1,951	$ 4,688
Accrued interest receivable from unit-holders		$ 177	$ 177	$ 457