Consolidated statements of operations - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Revenue:
Total revenue	$ 68,058	$ 64,969	$ 136,899	$ 126,237
Costs and expenses:
Operating	(25,355)	(26,464)	(51,992)	(51,789)
General and administrative expenses	(5,250)	(5,212)	(11,567)	(13,376)
Insurance expenses	(1,280)	(1,218)	(2,488)	(2,579)
Deferred compensation expense	(354)	(294)	(1,265)	(1,093)
Depreciation and amortization	(14,242)	(13,107)	(27,883)	(25,759)
Total costs and expenses	(46,481)	(46,295)	(95,195)	(94,596)
Earnings from unconsolidated affiliates	1,850	1,225	4,003	2,365
Gain from insurance proceeds		3,351		3,351
Operating income	23,427	23,250	45,707	37,357
Other expenses:
Interest expense	(7,204)	(9,708)	(16,418)	(18,550)
Amortization of deferred debt issuance costs	(627)	(632)	(1,270)	(1,382)
Total other expenses	(7,831)	(10,340)	(17,688)	(19,932)
Net earnings	15,596	12,910	28,019	17,425
External customers
Revenue:
Total revenue	60,894	57,837	122,563	111,604
Affiliate customers
Revenue:
Total revenue	$ 7,164	$ 7,132	$ 14,336	$ 14,633