Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Oct. 02, 2011
CURRENT ASSETS:
Cash and cash equivalents	$ 104,848	$ 90,494
Accounts receivable - net	700,480	657,179
Prepaid expenses and other current assets	48,168	84,612
Income taxes receivable	5,817	6,817
Total current assets	859,313	839,102
PROPERTY AND EQUIPMENT - NET	74,309	77,536
INVESTMENTS IN AND ADVANCES TO UNCONSOLIDATED JOINT VENTURES	3,279	3,454
GOODWILL	635,958	569,414
INTANGIBLE ASSETS - NET	74,231	81,053
OTHER ASSETS	23,940	23,429
TOTAL ASSETS	1,671,030	1,593,988
CURRENT LIABILITIES:
Accounts payable	154,003	164,819
Accrued compensation	128,086	110,937
Billings in excess of costs on uncompleted contracts	90,909	84,754
Deferred income taxes	20,809	22,870
Current portion of long-term debt	2,031	2,556
Estimated contingent earn-out liabilities	35,407	64,119
Other current liabilities	72,549	81,654
Total current liabilities	503,794	531,709
DEFERRED INCOME TAXES	24,268	25,394
LONG-TERM DEBT	81,047	144,868
OTHER LONG-TERM LIABILITIES	42,054	36,767
COMMITMENTS AND CONTINGENCIES
EQUITY:
Preferred stock - Authorized, 2,000 shares of $0.01 par value; no shares issued and outstanding at September 30, 2012, and October 2, 2011
Common stock - Authorized, 150,000 shares of $0.01 par value; issued and outstanding, 63,837 and 62,495 shares at September 30, 2012, and October 2, 2011, respectively	638	625
Additional paid-in capital	433,009	399,420
Accumulated other comprehensive income	31,017	4,754
Retained earnings	554,306	449,926
Tetra Tech stockholders' equity	1,018,970	854,725
Noncontrolling interests	897	525
TOTAL EQUITY	1,019,867	855,250
TOTAL LIABILITIES AND EQUITY	$ 1,671,030	$ 1,593,988