Basis of Presentation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended		6 Months Ended
	Mar. 25, 2019	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Accounting Policies [Abstract]
Equity commitment amount	$ 200,000
Preferred units issued (in shares)	100,000
Face value per unit (in dollars per share)	$ 1,000
Proceeds from issuance	$ 100,000
Offering costs	3,500
Remaining equity commitment	$ 100,000
Dividend rate	6.50%
Accretion		$ 3,151
Operating lease, weighted average discount rate		3.69%		3.69%
Finance lease, weighted average discount rate		2.80%		2.80%
Accumulated Amortization		$ 45,600		$ 45,600		$ 29,600
Amortization expense		$ 8,100	$ 8,100	$ 16,000	$ 13,300
Weighted average amortization period				11 years