Summary of Significant Accounting Policies and New Accounting Pronouncements - Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2014	Mar. 28, 2014	Dec. 27, 2013	Sep. 27, 2013	Jun. 30, 2013	Mar. 29, 2013	Dec. 28, 2012	Sep. 28, 2012	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012
Computation of Earnings Per Share, Basic and Diluted [Line Items]
Net income (loss) applicable to TRC Companies, Inc.	$ 5,037	$ 1,431	$ 3,096	$ 2,487	$ 24,779	$ 3,101	$ 4,123	$ 4,272	$ 12,051	$ 36,275	$ 33,575
Basic weighted-average common shares outstanding									29,594	28,843	27,781
Effect of dilutive stock options and restricted stock									546	758	1,041
Diluted weighted-average common shares outstanding									30,140	29,601	28,822
Basic earnings (loss) per common share (in dollars per share)	$ 0.17	$ 0.05	$ 0.10	$ 0.08	$ 0.85	$ 0.11	$ 0.14	$ 0.15	$ 0.41	$ 1.26	$ 1.21
Diluted earnings (loss) per common share (in dollars per share)	$ 0.17	$ 0.05	$ 0.10	$ 0.08	$ 0.83	$ 0.10	$ 0.14	$ 0.15	$ 0.40	$ 1.23	$ 1.16
Anti-dilutive stock-based awards excluded from the calculation									2,004	2,124	1,932