Employee Benefits (Details) (USD $)	12 Months Ended
	Dec. 31, 2011		Dec. 25, 2010	Dec. 26, 2009
Change in fair value of plan assets [Roll Forward]
Payable maximum period to be considered current (in months)	12M
Long-term liability	$ (32,839,000)		$ (18,249,000)
Percentage of gains and losses amortized over the average remaining service period (in hundredths)	10.00%
Weighted average assumptions in net periodic benefit calculations [Abstract]
Minimum annual assumed rate of increase in the per capita cost of covered benefits (in hundredths)	6.55%
Maximum annual assumed rate of increase in the per capita cost of covered benefits (in hundredths)	10.00%
Ultimate health care cost trend rate (in hundredths)	5.00%
Target allocation percentage [Abstract]
Company's target allocation minimum of equity securities (in hundredths)	60.00%
Company's target allocation maximum on fixed income securities (in hundredths)	25.00%
Company's target allocation maximum of alternative investments (in hundredths)	20.00%
One percent change assumptions [Abstract]
Increase in the accumulated postretirement benefit obligation	1,900,000
Increase in the service and interest cost components of net periodic postretirement benefit costs	100,000
Decrease in the accumulated postretirement benefit obligation	1,600,000
Decrease in the service and interest cost components of net periodic postretirement benefit costs	100,000
Defined Benefit Plan Disclosure [Line Items]
Plan assets	147,502,000
Approximate percentage of common stock invested in major industry (in hundredths)	88.00%
Approximate percentage of mutual funds actively managed (in hundredths)	30.00%
Percentage of mutual funds' assets that are invested in U.S equities (in hundredths)	32.00%
Approximate percentage of indexed mutual funds	70.00%
Percent of mutual funds' assets that are invested in non-U.S. equities (in hundredths)	57.00%
Percent of mutual funds' assets that are invested in non-U.S. fixed income securities (in hundredths)	11.00%
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Number of funds that can be redeemed quarterly	1
Number of days notice needed to redeem quarterly funding from investments in limited partnerships (in days)	60D
Number of days notice needed to redeem monthly funding from investments in limited partnerships (in days)	30D
I.A.M Plan Trusts [Abstract]
Number of collective bargaining agreements	2
Percentage of employer contributions (in hundredths)	5.00%
Pension expense under the I.A.M. pension plan trusts	900,000		700,000	1,400,000
Maximum percentage funded in the red zone, under the Pension Protection act of 2006 (in hundredths)	65.00%
Maximum percentage funded in the yellow zone, under the Pension Protection act of 2006 (in hundredths)	80.00%
Maximum percentage funded in the green zone, under the Pension Protection act of 2006 (in hundredths)	80.00%
Compensation expense for the Company's matching contribution	3,000,000		2,500,000	2,400,000
Contributions to UMWA 1992 Benefit Plan	338,000		478,000	475,000
Limited partnerships [Member]
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Beginning balance	11,590,000
Purchases	1,068,000
Redemptions	(1,668,000)
Net appreciation in fair value	155,000
Ending balance	11,145,000
Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	89,259,000
Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	47,098,000
Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	11,145,000
Cash and money market funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	11,707,000
Cash and money market funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	11,707,000
Cash and money market funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0
Cash and money market funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0
Common stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	58,498,000	[1]
Common stock [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	58,498,000	[1]
Common stock [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	[1]
Common stock [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	[1]
Mutual funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	66,152,000	[2]
Mutual funds [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	19,054,000	[2]
Mutual funds [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	47,098,000	[2]
Mutual funds [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0	[2]
Limited partnerships [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	11,145,000
Limited partnerships [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0
Limited partnerships [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	0
Limited partnerships [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan Disclosure [Line Items]
Plan assets	11,145,000
Pension benefits [Member]
Change in benefit obligation [Roll Forward]
Obligation at beginning of year	174,464,000		164,644,000
Service cost	1,394,000		823,000
Interest cost	9,051,000		9,374,000
Actuarial loss (gain)	6,077,000		12,417,000
Benefit payments	(10,942,000)		(10,636,000)
Effect of curtailments and settlements	0		0
Foreign currency translation adjustment	297,000		(2,158,000)
Obligation at end of year	180,341,000		174,464,000	164,644,000
Change in fair value of plan assets [Roll Forward]
Beginning Balance	156,215,000		147,703,000
Actual return on plan assets	(1,306,000)		17,585,000
Employer contributions	3,094,000		3,042,000
Benefit payments	(10,942,000)		(10,636,000)
Foreign currency translation adjustment	441,000		(1,479,000)
Ending Balance	147,502,000		156,215,000	147,703,000
Underfunded status at end of year	(32,839,000)		(18,249,000)
Unrecognized net actuarial loss	58,436,000		41,935,000
Unrecognized prior service cost	3,000		4,000
Current liability	0		0
Long-term liability	(32,839,000)		(18,249,000)
Total underfunded status	(32,839,000)		(18,249,000)
Service cost	1,394,000		823,000	865,000
Interest cost	9,051,000		9,374,000	8,907,000
Expected return on plan assets	(11,569,000)		(11,443,000)	(10,732,000)
Amortization of prior service cost	2,000		294,000	305,000
Amortization of net loss (gain)	2,346,000		2,307,000	833,000
Net periodic benefit cost (income)	1,224,000		1,355,000	178,000
Weighted average assumptions in benefit obligations calculations [Abstract]
Discount rate (in hundredths)	4.80%		5.25%
Expected long-term return on plan assets (in hundredths)	7.11%		7.51%
Rate of compensation increases (in hundredths)
Rate of inflation (in hundredths)	3.00%		3.40%
Weighted average assumptions in net periodic benefit calculations [Abstract]
Discount rate (in hundredths)	5.25%		5.77%	6.44%
Expected long-term return on plan assets (in hundredths)	7.51%		8.04%	8.12%
Rate of compensation increases (in hundredths)	3.40%		3.75%	2.75%
Asset category [Abstract]
Equity securities (includes equity mutual funds) (in hundredths)	80.00%		73.00%
Fixed income securities (includes fixed income mutual funds) (in hundredths)	5.00%		4.00%
Cash and equivalents (includes money market funds) (in hundredths)	8.00%		16.00%
Alternative investments (in hundredths)	7.00%		7.00%
Total (in hundredths)	100.00%		100.00%
Future expected benefit payments [Abstract]
2012	10,311,000
2013	10,384,000
2014	10,513,000
2015	10,657,000
2016	10,783,000
2017-2021	53,809,000
Total	106,457,000
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Company's expected contribution to benefit plans in next fiscal year	1,500,000
Other benefits [Member]
Change in benefit obligation [Roll Forward]
Obligation at beginning of year	21,083,000		21,381,000
Service cost	344,000		275,000
Interest cost	993,000		1,334,000
Actuarial loss (gain)	(1,369,000)		(697,000)
Benefit payments	(937,000)		(1,100,000)
Effect of curtailments and settlements	0		(167,000)
Foreign currency translation adjustment	(169,000)		57,000
Obligation at end of year	19,945,000		21,083,000	21,381,000
Change in fair value of plan assets [Roll Forward]
Beginning Balance	0		0
Actual return on plan assets	0		0
Employer contributions	937,000		1,100,000
Benefit payments	(937,000)		(1,100,000)
Foreign currency translation adjustment	0		0
Ending Balance	0		0	0
Underfunded status at end of year	(19,945,000)		(21,083,000)
Unrecognized net actuarial loss	118,000		1,455,000
Unrecognized prior service cost	17,000		16,000
Current liability	(1,333,000)		(1,362,000)
Long-term liability	(18,612,000)		(19,721,000)
Total underfunded status	(19,945,000)		(21,083,000)
Service cost	344,000		273,000	235,000
Interest cost	993,000		1,333,000	1,824,000
Amortization of prior service cost	(3,000)		1,000	2,000
Amortization of net loss (gain)	(2,000)		156,000	156,000
Effect of curtailments and settlements	0		25,000	28,000
Net periodic benefit cost (income)	1,332,000		1,788,000	2,245,000
Weighted average assumptions in benefit obligations calculations [Abstract]
Discount rate (in hundredths)	4.97%		5.39%
Rate of compensation increases (in hundredths)	5.04%		5.04%
Rate of inflation (in hundredths)
Weighted average assumptions in net periodic benefit calculations [Abstract]
Discount rate (in hundredths)	5.39%		6.08%	6.24%
Expected long-term return on plan assets (in hundredths)
Rate of compensation increases (in hundredths)	5.04%		5.04%	5.04%
Future expected benefit payments [Abstract]
2012	1,333,000
2013	1,350,000
2014	1,370,000
2015	1,433,000
2016	1,386,000
2017-2021	7,328,000
Total	14,200,000
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Company's expected contribution to benefit plans in next fiscal year	1,300,000
U.K Plan [Member]
Change in fair value of plan assets [Roll Forward]
Percent of above benefit obligation on company sponsored UK pension plan (in hundredths)	36.00%		35.00%
Percent above plan assets on company sponsored UK pension plan (in hundredths)	33.00%		32.00%
Defined benefit plan, amortization of net gains (losses)	$ (3,700,000)

[1] Approximately 88 percent of common stock represents investments in U.S. companies primarily in the health care, utilities, financials, consumer staples, industrials, information technology, and telecommunications sectors. All investments in common stock are listed on U.S. stock exchanges.

[2] Approximately 30 percent of mutual funds are actively managed funds. Additionally, 32 percent of the mutual funds' assets are invested in U.S. equities, 57 percent in non-U.S. equities, and 11 percent in non-U.S. fixed income securities.