CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016
Cash flows from operating activities:
Net income	$ 30,908	$ 8,203
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation	28,139	30,850
Amortization of intangible assets	3,611	3,239
Intangible asset impairment	477
Stock-based compensation expense	690	710
Gain on sale of property and equipment	(3,208)	(2,293)
Changes in assets and liabilities:
Customer retention deposits	(425)	(435)
Accounts receivable	43,792	2,514
Costs and estimated earnings in excess of billings	(19,572)	(17,151)
Other current assets	11,920	2,708
Other long-term assets	380	(747)
Accounts payable	(37,060)	(11,065)
Billings in excess of costs and estimated earnings	45,791	(17,584)
Accrued expenses and other current liabilities	8,154	7,337
Other long-term liabilities	2,692	(788)
Net cash provided by operating activities	116,289	5,498
Cash flows from investing activities:
Purchase of property and equipment	(44,697)	(42,140)
Proceeds from sale of property and equipment	4,664	5,723
Cash paid for acquisitions	(66,205)	(4,108)
Net cash used in investing activities	(106,238)	(40,525)
Cash flows from financing activities:
Repayment of capital leases	(117)	(468)
Repayment of long-term debt	(24,562)	(24,262)
Proceeds from issuance of common stock purchased under a long-term incentive plan	1,148	1,439
Repurchase of common stock	(4,999)
Dividends paid	(5,668)	(5,689)
Net cash used in financing activities	(34,198)	(28,980)
Net change in cash and cash equivalents	(24,147)	(64,007)
Cash and cash equivalents at beginning of the period	135,823	161,122
Cash and cash equivalents at end of the period	111,676	97,115
Cash paid:
Interest	4,663	4,412
Income taxes, net of refunds received	15,554	1,299
SUPPLEMENTAL DISCLOSURES OF NONCASH INVESTING AND FINANCING ACTIVITIES
Obligations incurred for the acquisition of property	4,163
Dividends declared and not yet paid	$ 2,829	$ 2,847