Condensed Consolidated Statements of Income (Loss) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Condensed Consolidated Statements of Income (Loss)
Operating revenues	$ 89,222	$ 94,510
Operating expenses:
Cost of revenues (exclusive of depreciation and amortization)	42,088	41,191
Selling, general and administrative	27,625	29,632
Depreciation and amortization	23,333	21,269
Total operating expenses	93,046	92,092
Operating income (loss)	(3,824)	2,418
Other income (expense):
Interest expense	(4,136)	(3,993)
Retirement plan	710	(1,763)
Total other expense	(3,426)	(5,756)
Loss before income tax benefit	(7,250)	(3,338)
Income tax benefit	(1,514)	(1,386)
Net loss	$ (5,736)	$ (1,952)
Net loss per common share -
Basic (in dollars per share)	$ (0.49)	$ (0.17)
Diluted (in dollars per share)	$ (0.49)	$ (0.17)
Weighted average shares used to compute net loss per common share -
Basic (in shares)	11,597,918	11,529,046
Diluted (in shares)	11,597,918	11,529,046