Employee Benefit Plans - fair values of pension plan assets (Details) (USD $) In Thousands, unless otherwise specified	Nov. 25, 2012
Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 894,362
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,585
Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	883,940
Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,837
Cash and cash equivalents [Member] | Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,585
Cash and cash equivalents [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,585
Cash and cash equivalents [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
Cash and cash equivalents [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0
U.S. large cap [Member] | Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	208,722	[1]
U.S. large cap [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[1]
U.S. large cap [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	208,722	[1]
U.S. large cap [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[1]
U.S. small cap [Member] | Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	37,356	[1]
U.S. small cap [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[1]
U.S. small cap [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	37,356	[1]
U.S. small cap [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[1]
International [Member] | Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	158,281	[1]
International [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[1]
International [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	158,281	[1]
International [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[1]
Fixed income securities [Member] | Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	397,706	[2]
Fixed income securities [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[2]
Fixed income securities [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	397,706	[2]
Fixed income securities [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[2]
Real estate [Member] | Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	69,526	[3]
Real estate [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[3]
Real estate [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	69,526	[3]
Real estate [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[3]
Private equity [Member] | Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,837	[4]
Private equity [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[4]
Private equity [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[4]
Private equity [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3,837	[4]
Hedge funds [Member] | Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,733	[5]
Hedge funds [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[5]
Hedge funds [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5,733	[5]
Hedge funds [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[5]
Other [Member] | Total [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,616	[6]
Other [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0	[6]
Other [Member] | Significant Observable Inputs (Level 2) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6,616	[6]
Other [Member] | Significant Unobservable Inputs (Level 3) [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0	[6]

[1] Primarily comprised of equity index funds that track various market indices.

[2] Predominantly includes bond index funds that invest in U.S. government and investment grade corporate bonds.

[3] Primarily comprised of investments in U.S. Real Estate Investment Trusts.

[4] Represents holdings in a diversified portfolio of private equity funds and direct investments in companies located primarily in North America. Fair values are determined by investment fund managers using primarily unobservable market data.

[5] Primarily invested in a diversified portfolio of equities, bonds, alternatives and cash with a low tolerance for capital loss.

[6] Primarily relates to accounts held and managed by a third-party insurance company for employee-participants in Belgium. Fair values are based on accumulated plan contributions plus a contractually-guaranteed return plus a share of any incremental investment fund profits.