CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Cash flows from operating activities:
Net income	$ 8,746	$ 4,221	$ 24,491	$ 12,438
Adjustments to reconcile net income to net cash flows provided by (used in) operating activities -
Depreciation and amortization of property and equipment	6,420	4,980	18,167	13,794
Amortization of intangible assets	84	84	251	251
Stock-based compensation expense	688	146	2,029	1,100
Deferred income taxes	197	(622)	197	(576)
Gain on sale of property and equipment	(387)	(428)	(707)	(728)
Other non-cash items	35	17	103	78
Changes in operating assets and liabilities
Accounts receivable, net	(10,269)	(37,261)	(37,529)	(29,831)
Costs and estimated earnings in excess of billings on uncompleted contracts	(8,941)	4,233	(19,413)	(20,947)
Construction materials inventory		(2,754)	4,003	(2,754)
Receivable for insurance claims in excess of deductibles	(1,401)	35	(1,160)	(714)
Other assets	1,135	2,656	2,379	4,223
Accounts payable	7,176	4,972	18,897	21,389
Billings in excess of costs and estimated earnings on uncompleted contracts	1,202	(3,014)	5,120	(6,566)
Accrued self insurance	1,291	2,797	779	3,799
Other liabilities	6,617	967	5,133	315
Net cash flows provided by (used in) operating activities	12,593	(18,971)	22,740	(4,729)
Cash flows from investing activities:
Proceeds from sale of property and equipment	513	508	877	808
Purchases of property and equipment	(11,665)	(11,338)	(32,094)	(34,162)
Net cash flows used in investing activities	(11,152)	(10,830)	(31,217)	(33,354)
Cash flows from financing activities:
Repayments on term loan				(20,000)
Net borrowings (repayments) on revolving credit facility	(10,000)	10,000	(10,000)	10,000
Employee stock option transactions	719	711	864	1,290
Excess tax benefit from stock-based awards	139	1,228	174	1,672
Debt issuance costs			(13)
Other financing activities			38	45
Net cash flows provided by (used in) financing activities	(9,142)	11,939	(8,937)	(6,993)
Net decrease in cash and cash equivalents	(7,701)	(17,862)	(17,414)	(45,076)
Cash and cash equivalents:
Beginning of period	24,300	35,409	34,013	62,623
End of period	$ 16,599	$ 17,547	$ 16,599	$ 17,547

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The aggregate expense charged against earnings to allocate the cost of intangible assets (nonphysical assets not used in production) in a systematic and rational manner to the periods expected to benefit from such assets. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method.