Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Mar. 30, 2014	Sep. 29, 2013
Current assets:
Cash and cash equivalents	$ 167,225	$ 129,305
Accounts receivable - net	656,481	660,847
Prepaid expenses and other current assets	52,325	61,446
Income taxes receivable	13,727	20,044
Total current assets	889,758	871,642
Property and equipment - net	80,352	88,026
Investments in and advances to unconsolidated joint ventures	2,494	2,198
Goodwill	709,502	722,792
Intangible assets - net	70,983	86,929
Other long-term assets	23,943	27,505
Total assets	1,777,032	1,799,092
Current liabilities:
Accounts payable	153,597	142,813
Accrued compensation	93,511	114,810
Billings in excess of costs on uncompleted contracts	85,970	79,507
Deferred income taxes	19,722	18,170
Current portion of long-term debt	8,532	4,311
Estimated contingent earn-out liabilities	27,265	23,281
Other current liabilities	71,430	100,241
Total current liabilities	460,027	483,133
Deferred income taxes	27,237	30,525
Long-term debt	198,219	203,438
Long-term estimated contingent earn-out liabilities	21,823	58,508
Other long-term liabilities	27,803	24,685
Commitments and contingencies
Equity:
Preferred stock - Authorized, 2,000 shares of $0.01 par value; no shares issued and outstanding at March 30, 2014, and September 29, 2013
Common stock - Authorized, 150,000 shares of $0.01 par value; issued and outstanding, 65,068 and 64,134 shares at March 30, 2014, and September 29, 2013, respectively	650	641
Additional paid-in capital	464,354	443,099
Accumulated other comprehensive income (loss)	(35,449)	1,858
Retained earnings	611,188	552,165
Tetra Tech stockholders' equity	1,040,743	997,763
Noncontrolling interests	1,180	1,040
Total equity	1,041,923	998,803
Total liabilities and equity	$ 1,777,032	$ 1,799,092