Fair Value Measurements (Details) (USD $) In Thousands	Aug. 26, 2011	Feb. 28, 2011	Aug. 27, 2010
Active employees' medical plan trust assets [Member] | Quoted prices in active markets for identical assets and liabilities (Level 1) [Member] | Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Fair Value of Investments, measured on recurring basis	$ 3,296	$ 3,223	$ 4,118
Active employees' medical plan trust assets [Member] | Quoted prices in active markets for similar assets and liabilities (Level 2) [Member] | Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Fair Value of Investments, measured on recurring basis	0	0	0
Active employees' medical plan trust assets [Member] | Significant unobservable inputs (Level 3) [Member] | Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Fair Value of Investments, measured on recurring basis	0	0	0
Active employees' medical plan trust assets [Member] | Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Fair Value of Investments, measured on recurring basis	3,296	3,223	4,118
Deferred Compensation plan assets [Member] | Quoted prices in active markets for identical assets and liabilities (Level 1) [Member] | Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Fair Value of Investments, measured on recurring basis	8,251	6,871	5,662
Deferred Compensation plan assets [Member] | Quoted prices in active markets for similar assets and liabilities (Level 2) [Member] | Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Fair Value of Investments, measured on recurring basis	0	0	0
Deferred Compensation plan assets [Member] | Significant unobservable inputs (Level 3) [Member] | Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Fair Value of Investments, measured on recurring basis	0	0	0
Deferred Compensation plan assets [Member] | Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Fair Value of Investments, measured on recurring basis	8,251	6,871	5,662
Quoted prices in active markets for identical assets and liabilities (Level 1) [Member] | Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Total	11,547	10,094	9,780
Quoted prices in active markets for identical assets and liabilities (Level 1) [Member] | Nonrecurring [Member]
Assets measured on a recurring and non-recurring basis:
Assets held for sale	0	0	0
Total	0	0	0
Quoted prices in active markets for similar assets and liabilities (Level 2) [Member] | Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Total	0	0	0
Quoted prices in active markets for similar assets and liabilities (Level 2) [Member] | Nonrecurring [Member]
Assets measured on a recurring and non-recurring basis:
Assets held for sale	5,282	5,282	5,557
Total	5,282	5,282	5,557
Significant unobservable inputs (Level 3) [Member] | Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Total	0	0	0
Significant unobservable inputs (Level 3) [Member] | Nonrecurring [Member]
Assets measured on a recurring and non-recurring basis:
Assets held for sale	0	0	0
Total	0	0	0
Recurring [Member]
Assets measured on a recurring and non-recurring basis:
Total	11,547	10,094	9,780
Nonrecurring [Member]
Assets measured on a recurring and non-recurring basis:
Assets held for sale	5,282	5,282	5,557
Total	$ 5,282	$ 5,282	$ 5,557