Acquisitions - Fair Value of Identifiable Intangible Assets (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 30, 2012
Critical Infrastructure Business
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Value	$ 2.0
Estimated Weighted Average Amortization Period	1 year 2 months 12 days
Critical Infrastructure Business | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Value	1.1
Estimated Weighted Average Amortization Period	1 year 3 months 18 days
Critical Infrastructure Business | Funded backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Value	0.9
Estimated Weighted Average Amortization Period	1 year
Composite Engineering, Inc.
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Value	38.0
Estimated Weighted Average Amortization Period	3 years 6 months
Composite Engineering, Inc. | Trade name
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Value	0.5
Estimated Weighted Average Amortization Period	6 years
Composite Engineering, Inc. | Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Value	18.5
Estimated Weighted Average Amortization Period	5 years 6 months
Composite Engineering, Inc. | Funded backlog
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Value	$ 19.0
Estimated Weighted Average Amortization Period	1 year 6 months