UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Income Statement [Abstract]
Operating revenues	$ 151,782	$ 156,836	$ 458,920	$ 379,716
Operating expenses:
Cost of goods and services, exclusive of depreciation and amortization shown separately below	55,834	58,317	162,976	140,354
Selling, general and administrative, exclusive of depreciation and amortization shown separately below	42,199	40,369	125,374	96,263
Integration and acquisition expenses	1,706	15,272	9,873	35,801
Depreciation and amortization	42,568	46,807	132,297	96,961
Total operating expenses	142,307	160,765	430,520	369,379
Operating income (loss)	9,475	(3,929)	28,400	10,337
Other income (expense):
Interest expense	(9,823)	(8,845)	(28,312)	(16,369)
Gain (loss) on investments, net	202	127	395	237
Non-operating income (loss), net	1,003	1,400	3,482	2,910
Income (loss) before income taxes	857	(11,247)	3,965	(2,885)
Income tax expense (benefit)	(2,677)	(3,651)	(1,830)	(2,174)
Net income (loss)	3,534	(7,596)	5,795	(711)
Other comprehensive income (loss):
Unrealized gain (loss) on interest rate hedge, net of tax	6	1,712	(770)	(2,573)
Comprehensive income (loss)	$ 3,540	$ (5,884)	$ 5,025	$ (3,284)
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.07	$ (0.16)	$ 0.12	$ (0.01)
Diluted (in dollars per share)	$ 0.07	$ (0.16)	$ 0.12	$ (0.01)
Weighted average shares outstanding, basic (in shares)	49,133	48,909	49,100	48,768
Weighted average shares outstanding, diluted (in shares)	49,959	48,909	49,869	48,768