Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Cash flows from operating activities:
Net income	$ 1,536	$ 6,121
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	65,772	57,321
Employee retirement benefits	(3,315)	(10,557)
Provision for uncollectibles	2,640	2,493
Stock based compensation	1,087	3,066
Deferred income taxes	1,633	4,770
Changes in operating assets and liabilities:
Receivables	(3,558)	(1,350)
Material and supplies	211	(685)
Prepaid expenses and other current assets	(2,538)	(1,421)
Accounts payable and accrued expenses	(3,222)	1,296
Advance billings and customer deposits	4,054	(50)
Other current liabilities	(693)	(568)
Other	1,988	1,380
Net cash provided by operating activities	65,595	61,816
Cash flows from investing activities:
Capital expenditures	(76,732)	(76,474)
Funds released from restricted cash account	400
Net cash used in investing activities	(76,332)	(76,474)
Cash flows from financing activities:
Proceeds from stock issuance	3,342
Refinancing costs	(150)
Proceeds from installment financing	2,779	2,085
Repayment of capital lease and installment financing	(3,083)	(2,014)
Repayment of debt	(2,250)	(2,250)
Taxes paid related to net share settlement of equity awards	(941)	(1,021)
Net cash used in financing activities	(303)	(3,200)
Net change in cash and cash equivalents	(11,040)	(17,858)
Cash and cash equivalents, beginning of year	39,885	49,551
Cash and cash equivalents, end of year	28,845	31,693
Supplemental disclosure of cash flow information:
Interest paid, net of amounts capitalized	$ 11,234	$ 11,033