Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016
Cash flows from operating activities:
Net income (loss)	$ (98,148)	$ 1,321
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	65,186	67,479
Deferred financing amortization	1,165	1,533
Loss on early extinguishment of debt	4,826
Employee retirement benefits	(1,624)	(6,430)
Provision for uncollectible receivables	2,791	2,908
Stock based compensation	2,050	1,722
Deferred income taxes	84,072	1,412
Changes in operating assets and liabilities:
Receivables	212	1,340
Material and supplies	1,140	282
Prepaid expenses and other current assets	(1,166)	(1,839)
Accounts payable and accrued expenses	(44)	6,067
Advance billings and customer deposits	20,677	(2,227)
Other current liabilities	(272)	(600)
Other	(100)	(22)
Net cash provided by operating activities	80,765	72,946
Cash flows from investing activities:
Capital expenditures	(75,718)	(78,334)
Net cash used in investing activities	(75,718)	(78,334)
Cash flows from financing activities:
Proceeds from borrowing	330,000
Proceeds from installment financing	1,260	1,698
Repayment of capital lease and installment financing	(2,989)	(2,680)
Repayment of borrowings	(302,701)	(2,250)
Refinancing costs	(6,295)	(688)
Taxes paid related to net share settlement of equity awards	(495)	(354)
Net cash provided by (used in) financing activities	18,780	(4,274)
Net change in cash, cash equivalents and restricted cash	23,827	(9,662)
Cash, cash equivalents and restricted cash, beginning of period	21,146	30,312
Cash, cash equivalents and restricted cash, end of period	$ 44,973	$ 20,650