Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Cash flows from operating activities
Net (loss) income	$ (13,114)	$ 21,882	$ 20,030
Depreciation and amortization	22,092	19,458	18,536
Deferred financing cost amortization	132	296	252
Bad debt (recovery) expense	255	(285)	442
Deferred income taxes	5,192	4,959	(1,013)
Stock-based compensation	2,712	2,542	1,614
Gain on bargain purchase of a business	0	(1,589)	0
Loss (gain) on sale of property and equipment	60	(459)	(518)
Excess tax benefit from stock option exercise	0	(96)	(1,476)
Change in operating assets and liabilities, net of effects of acquisitions of businesses:
Accounts receivable	26,135	(5,073)	(1,996)
Income tax receivable	(6,331)	(5,119)	2,453
Note receivable	39	1,246	(961)
Inventory	(370)	(1,519)	(734)
Prepaid expenses and other	(377)	(698)	1,608
Costs and estimated earnings in excess of billings on uncompleted contracts	10,991	(13,733)	(3,640)
Accounts payable	(12,970)	(7,651)	11,241
Accrued liabilities	(2,728)	3,024	270
Income tax payable	(262)	(50)	314
Billings in excess of costs and estimated earnings on uncompleted contracts, net	1,277	(3,241)	(6,030)
Deferred revenue	(57)	(55)	(56)
Net cash provided by operating activities	32,676	13,839	40,336
Cash flows from investing activities:
Proceeds from sale of property and equipment	841	827	1,095
Purchase of property and equipment	(14,894)	(29,050)	(22,693)
Acquisition of TW LaQuay Dredging (net of cash acquired)	0	(60,879)	0
Acquisition of business (net of cash acquired)	0	(6,653)	0
Net cash used in investing activities	(14,053)	(95,755)	(21,598)
Cash flows from financing activities:
Increase in loan costs	0	411	0
Payments on long-term debt	0	0	(34,125)
Purchase of treasury stock	(3,003)	0	0
Exercise of stock options	185	669	1,938
Excess tax benefit from stock option exercise	0	96	1,476
Proceeds from sale of common stock, net of offering costs	0	0	90,997
Net cash (used in) provided by financing activities	(2,818)	354	60,286
Net change in cash and cash equivalents	15,805	(81,562)	79,024
Cash and cash equivalents at beginning of period	23,174	104,736	25,712
Cash and cash equivalents at end of period	38,979	23,174	104,736
Supplemental disclosures of cash flow information:
Interest	212	547	553
Income Taxes Paid, Net	(4,948)	12,149	9,781
Non-cash capital expenditures	$ 0	$ 1,110	$ 42