Acquisitions - Composite Engineering, Inc. (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	0 Months Ended		3 Months Ended								12 Months Ended				0 Months Ended		12 Months Ended		0 Months Ended
	May 14, 2012	Feb. 11, 2011	Dec. 29, 2013	Sep. 29, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 30, 2012	Sep. 30, 2012	Jun. 24, 2012	Mar. 25, 2012	Dec. 29, 2013	Dec. 30, 2012	Dec. 25, 2011	Dec. 29, 2013 Revolving credit facility	Jul. 02, 2012 Composite Engineering, Inc.	May 14, 2012 Composite Engineering, Inc.	Dec. 30, 2012 Composite Engineering, Inc.	May 14, 2012 Composite Engineering, Inc. Revolving credit facility	Jul. 02, 2012 Composite Engineering, Inc. Restricted Stock Units (RSUs) Management	Jul. 02, 2012 Composite Engineering, Inc. Escrow account
Business Acquisition [Line Items]
Consideration transferred															$ 164,200,000
Aggregate amount of cash paid															135,000,000
Common stock issued for acquisitions (in shares)															4.0	20.0
Purchase price (in dollars per share)															$ 5.94	$ 5.00
Value of common stock exchanged as consideration															23,800,000
Contingent consideration, fair value																				10,700,000
Working capital adjustment															1,000,000
Consideration transferred, retirement of acquiree's debt															5,500,000
Tax deductible goodwill															136,300,000
Tax deductible goodwill, deduction realization period															15 years
Number of shares issued as part of long-term employment agreements																			2.0
Fair value of shares issued as part of long-term employment agreements																			11,900,000
Share-based compensation, period for recognition																			4 years
Gross proceeds from issuance of common stock	100,000,000	64,800,000														100,000,000
Proceeds from the issuance of common stock, net of issuance costs	97,000,000	61,100,000									0	97,000,000	61,100,000			97,000,000
Outstanding borrowings														0				40,000,000
Revenues											100,900,000	116,200,000	54,300,000				68,200,000
Operating income (loss)			$ 5,400,000	$ 6,100,000	$ 8,900,000	$ 11,400,000	$ (80,300,000)	$ 14,100,000	$ 7,400,000	$ 9,100,000	$ 31,800,000	$ (49,700,000)	$ 29,500,000				$ 1,600,000