Condensed Consolidated Balance Sheets (USD $) In Thousands, unless otherwise specified	Dec. 29, 2013	Sep. 29, 2013
Current assets:
Cash and cash equivalents	$ 160,796	$ 129,305
Accounts receivable - net	642,897	660,847
Prepaid expenses and other current assets	51,212	61,446
Income taxes receivable	25,346	20,044
Total current assets	880,251	871,642
Property and equipment - net	83,711	88,026
Investments in and advances to unconsolidated joint ventures	2,406	2,198
Goodwill	719,527	722,792
Intangible assets - net	78,686	86,929
Other long-term assets	24,092	27,505
Total assets	1,788,673	1,799,092
Current liabilities:
Accounts payable	137,373	142,813
Accrued compensation	101,267	114,810
Billings in excess of costs on uncompleted contracts	92,179	79,507
Deferred income taxes	19,952	18,170
Current portion of long-term debt	6,012	4,311
Estimated contingent earn-out liabilities	24,380	23,281
Other current liabilities	74,216	100,241
Total current liabilities	455,379	483,133
Deferred income taxes	29,514	30,525
Long-term debt	200,859	203,438
Long-term estimated contingent earn-out liabilities	56,114	58,508
Other long-term liabilities	28,565	24,685
Commitments and contingencies
Equity:
Preferred stock - Authorized, 2,000 shares of $0.01 par value; no shares issued and outstanding at December 29, 2013, and September 29, 2013
Common stock - Authorized, 150,000 shares of $0.01 par value; issued and outstanding, 64,738 and 64,134 shares at December 29, 2013, and September 29, 2013, respectively	647	641
Additional paid-in capital	456,514	443,099
Accumulated other comprehensive income (loss)	(19,413)	1,858
Retained earnings	579,480	552,165
Tetra Tech stockholders' equity	1,017,228	997,763
Noncontrolling interests	1,014	1,040
Total equity	1,018,242	998,803
Total liabilities and equity	$ 1,788,673	$ 1,799,092