Business Combinations (Details Textual) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Oct. 03, 2011
Business Combinations (Textual) [Abstract]
Contributing revenues	$ 145,237,000	$ 131,139,000	$ 452,193,000	$ 382,233,000
Net income attributable to Michael Baker Corporation	981,000	7,233,000	5,125,000	12,918,000
Business Combinations (Additional Textual) [Abstract]
Cost of stock acquired					100.00%
Stock Purchase Agreement (SPA) to acquire					49,300,000
Net Working Capital adjustment					5,000,000
Professional liability tail insurance premiums(RBF to fund)	1,200,000		1,200,000
Payment for stock acquired	45,700,000		45,700,000
Common stock issued			203,218
RBF consulting [Member]
Business Combinations (Textual) [Abstract]
Acquisition related amortization of intangible assets	1,500,000		4,400,000
Net income attributable to Michael Baker Corporation	900,000		2,800,000
Other Comprehensive Income (Loss) [Member] | RBF consulting [Member]
Business Combinations (Textual) [Abstract]
Contributing revenues	23,100,000		73,400,000
Common Stock [Member]
Business Combinations (Textual) [Abstract]
Common stock with a fair market value	$ 3,600,000		$ 3,600,000