UNAUDITED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Cash flows from operating activities:
Net income	$ 40,609	$ 23,439
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation and amortization of property and equipment	32,021	30,153
Amortization of intangible assets	3,009	2,888
Stock-based compensation expense	3,804	3,261
Deferred income taxes	712	339
Gain on sale of property and equipment	(1,967)	(2,548)
Other non-cash items	654	631
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable, net	(12,869)	(27,327)
Contract assets, net	(4,754)	(38,910)
Receivable for insurance claims in excess of deductibles	3,103	1,626
Other assets	7,074	(771)
Accounts payable	7,596	37,874
Contract liabilities	20,161	(397)
Accrued self insurance	(2,257)	(358)
Other liabilities	31,730	1,845
Net cash flows provided by operating activities	128,626	31,745
Cash flows from investing activities:
Proceeds from sale of property and equipment	2,147	2,898
Cash paid for acquired business	0	(79,720)
Purchases of property and equipment	(27,470)	(39,354)
Net cash flows used in investing activities	(25,323)	(116,176)
Cash flows from financing activities:
Net borrowings (repayments) under revolving lines of credit	(65,189)	67,668
Borrowings under equipment notes	0	24,037
Payment of principal obligations under equipment notes	(30,441)	(3,307)
Payment of principal obligations under finance leases	(914)	(857)
Proceeds from exercise of stock options	306	325
Debt refinancing costs	0	(1,132)
Repurchase of common shares	(426)	(778)
Other financing activities	60	60
Net cash flows provided by (used in) financing activities	(96,604)	86,016
Effect of exchange rate changes on cash	(150)	53
Net increase in cash and cash equivalents	6,549	1,638
Cash and cash equivalents:
Beginning of period	12,397	7,507
End of period	$ 18,946	$ 9,145