Members' Equity Members' Equity (AOCI) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	$ (5,303)	$ (7,099)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	8,204	(6,953)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	5,066	8,749
Other Comprehensive Income (Loss), Net of Tax	13,270	1,796	$ 4,834
Ending balance	7,967	(5,303)	(7,099)
Unrealized Gain (Loss) on Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(5,279)	(6,976)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	8,035	(6,851)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	5,066	8,548
Other Comprehensive Income (Loss), Net of Tax	13,101	1,697
Ending balance	7,822	(5,279)	(6,976)
Unrealized Gain (Loss) on Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	(24)	(123)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	163	(102)
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	201
Other Comprehensive Income (Loss), Net of Tax	163	99
Ending balance	139	(24)	(123)
Unrecognized Pension Liability [Member]
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Beginning balance	0	0
Other Comprehensive Income (Loss), before Reclassifications, before Tax	6	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, before Tax	0	0
Other Comprehensive Income (Loss), Net of Tax	6	0
Ending balance	$ 6	$ 0	$ 0