CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Cash flows from operating activities:
Net income	$ 9,535	$ 3,717	$ 15,745	$ 8,217
Adjustments to reconcile net income to net cash flows provided by operating activities -
Depreciation and amortization of property and equipment	6,047	4,567	11,747	8,814
Amortization of intangible assets	83	83	167	167
Stock-based compensation expense	647	606	1,341	954
Deferred income taxes		46		46
Gain on sale of property and equipment	(193)	(229)	(320)	(300)
Other non-cash items	34	17	68	61
Changes in operating assets and liabilities
Accounts receivable, net	1,158	(7,886)	(27,260)	7,430
Costs and estimated earnings in excess of billings on uncompleted contracts	(293)	(19,069)	(10,472)	(25,180)
Construction materials inventory	1,542		4,003
Receivable for insurance claims in excess of deductibles	61	(786)	241	(749)
Other assets	654	(2,118)	1,244	1,123
Accounts payable	5,544	22,273	11,721	16,417
Billings in excess of costs and estimated earnings on uncompleted contracts	113	(872)	3,918	(3,552)
Accrued self insurance	135	913	(512)	1,002
Other liabilities	(2,912)	(814)	(1,484)	(208)
Net cash flows provided by operating activities	22,155	448	10,147	14,242
Cash flows from investing activities:
Proceeds from sale of property and equipment	224	229	364	300
Purchases of property and equipment	(12,099)	(10,601)	(20,429)	(22,824)
Net cash flows used in investing activities	(11,875)	(10,372)	(20,065)	(22,524)
Cash flows from financing activities:
Repayments on term loan				(20,000)
Net borrowings (repayments) on revolving credit facility	10,000
Employee stock option transactions	219	300	145	579
Excess tax benefit from stock-based awards	15	275	35	444
Debt issuance costs	(2)		(13)
Other financing activities	38	45	38	45
Net cash flows provided by (used in) financing activities	10,270	620	205	(18,932)
Net increase (decrease) in cash and cash equivalents	20,550	(9,304)	(9,713)	(27,214)
Cash and cash equivalents:
Beginning of period	3,750	44,713	34,013	62,623
End of period	$ 24,300	$ 35,409	$ 24,300	$ 35,409

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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.