UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE INCOME (LOSS) [Abstract]
Operating revenues	$ 130,309	$ 85,701	$ 222,880	$ 169,989
Operating expenses:
Cost of goods and services, exclusive of depreciation and amortization shown separately below	50,296	30,280	82,057	60,970
Selling, general and administrative, exclusive of depreciation and amortization shown separately below	33,694	18,606	55,120	36,718
Integration and acquisition expenses	20,054	402	20,386	1,024
Depreciation and amortization	32,415	17,663	50,154	34,001
Total operating expenses	136,459	66,951	207,717	132,713
Operating income (loss)	(6,150)	18,750	15,163	37,276
Other income (expense):
Interest expense	(5,904)	(1,940)	(7,524)	(3,855)
Gain on investments, net	21	98	109	200
Non-operating income, net	146	442	614	874
Income (loss) before income taxes	(11,887)	17,350	8,362	34,495
Income tax expense (benefit)	(4,892)	6,876	1,477	13,735
Net income (loss)	(6,995)	10,474	6,885	20,760
Other comprehensive income (loss):
Unrealized gain (loss) on interest rate hedge, net of tax	(3,238)	326	(4,285)	(581)
Comprehensive income (loss)	$ (10,233)	$ 10,800	$ 2,600	$ 20,179
Earnings (loss) per share:
Basic (in dollars per share)	$ (0.14)	$ 0.22	$ 0.14	$ 0.43
Diluted (in dollars per share)	$ (0.14)	$ 0.21	$ 0.14	$ 0.42
Weighted average shares outstanding, basic (in shares)	48,830	48,380	48,696	48,343
Weighted average shares outstanding, diluted (in shares)	48,830	49,004	49,415	48,927