UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Cash flows from operating activities:
Net income	$ 23,317	$ 12,978
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation and amortization of property and equipment	21,324	19,714
Amortization of intangible assets	2,431	1,469
Stock-based compensation expense	2,173	2,153
Deferred income taxes	537	23
Gain on sale of property and equipment	(1,489)	(1,397)
Other non-cash items	267	783
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable, net	46,353	(24,468)
Contract assets, net	(7,658)	(14,218)
Receivable for insurance claims in excess of deductibles	4,934	568
Other assets	7,198	(3,552)
Accounts payable	(38,342)	27,242
Contract liabilities	23,271	(5,035)
Accrued self insurance	(5,843)	(692)
Other liabilities	19,450	(8,169)
Net cash flows provided by operating activities	97,923	7,399
Cash flows from investing activities:
Proceeds from sale of property and equipment	1,633	1,658
Purchases of property and equipment	(16,938)	(27,961)
Net cash flows used in investing activities	(15,305)	(26,303)
Cash flows from financing activities:
Net repayments under revolving lines of credit	(70,423)	(5,896)
Borrowings under equipment notes	0	24,038
Payment of principal obligations under equipment notes	(13,433)	(1,455)
Payment of principal obligations under finance leases	(616)	(575)
Proceeds from exercise of stock options	82	284
Repurchase of common shares	(425)	(778)
Other financing activities	49	36
Net cash flows provided by (used in) financing activities	(84,766)	15,654
Effect of exchange rate changes on cash	(258)	98
Net decrease in cash and cash equivalents	(2,406)	(3,152)
Cash and cash equivalents:
Beginning of period	12,397	7,507
End of period	$ 9,991	$ 4,355