Fair Value Hierarchy of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) (USD $) | Aug. 29, 2014 | Feb. 28, 2014 |
In Millions, unless otherwise specified |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Restricted Cash and Cash Equivalents | $7.70 | $9 |
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 4.4 | 5.6 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Cash and Cash Equivalents, Fair Value Disclosure | 155.7 | 201.8 |
Foreign Currency Contract, Asset, Fair Value Disclosure | 0 | 0 |
Assets, Fair Value Disclosure | 166.7 | 218.6 |
Liabilities, Fair Value Disclosure [Abstract] | ' | ' |
Foreign Currency Contracts, Liability, Fair Value Disclosure | 0 | 0 |
Liabilities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Government Agencies Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Corporate Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | US Government-sponsored Enterprises Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 3.3 | 7.8 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal Bonds [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | ' | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Other Debt Obligations [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Auction Rate Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Canadian Asset Backed Commercial Paper Restructuring Notes [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Cash and Cash Equivalents, Fair Value Disclosure | 0 | 0 |
Restricted Cash and Cash Equivalents | 0 | 0 |
Foreign Currency Contract, Asset, Fair Value Disclosure | 5 | 0.3 |
Assets, Fair Value Disclosure | 79.7 | 115.7 |
Liabilities, Fair Value Disclosure [Abstract] | ' | ' |
Foreign Currency Contracts, Liability, Fair Value Disclosure | -0.7 | -3.2 |
Liabilities, Fair Value Disclosure | -0.7 | -3.2 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 19.2 | 48.9 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 44.5 | 48 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | US Government-sponsored Enterprises Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 4.4 | 5.6 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal Bonds [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | ' | 3.4 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Other Debt Obligations [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 2.7 | 5.8 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Auction Rate Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Canadian Asset Backed Commercial Paper Restructuring Notes [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 3.9 | 3.7 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Cash and Cash Equivalents, Fair Value Disclosure | 0 | 0 |
Restricted Cash and Cash Equivalents | 0 | 0 |
Foreign Currency Contract, Asset, Fair Value Disclosure | 0 | 0 |
Assets, Fair Value Disclosure | 9.7 | 9.6 |
Liabilities, Fair Value Disclosure [Abstract] | ' | ' |
Foreign Currency Contracts, Liability, Fair Value Disclosure | 0 | 0 |
Liabilities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Government Agencies Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Corporate Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | US Government-sponsored Enterprises Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal Bonds [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | ' | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Other Debt Obligations [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Auction Rate Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 9.7 | 9.6 |
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Canadian Asset Backed Commercial Paper Restructuring Notes [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Cash and Cash Equivalents, Fair Value Disclosure | 155.7 | 201.8 |
Restricted Cash and Cash Equivalents | 7.7 | 9 |
Foreign Currency Contract, Asset, Fair Value Disclosure | 5 | 0.3 |
Assets, Fair Value Disclosure | 256.1 | 343.9 |
Liabilities, Fair Value Disclosure [Abstract] | ' | ' |
Foreign Currency Contracts, Liability, Fair Value Disclosure | -0.7 | -3.2 |
Liabilities, Fair Value Disclosure | -0.7 | -3.2 |
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | US Government Agencies Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 19.2 | 48.9 |
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Corporate Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 44.5 | 48 |
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | US Government-sponsored Enterprises Debt Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 3.3 | 7.8 |
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal Bonds [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | ' | 3.4 |
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Other Debt Obligations [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 2.7 | 5.8 |
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Auction Rate Securities [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | 9.7 | 9.6 |
Fair Value, Measurements, Recurring [Member] | Estimate of Fair Value, Fair Value Disclosure [Member] | Canadian Asset Backed Commercial Paper Restructuring Notes [Member] | ' | ' |
Assets, Fair Value Disclosure [Abstract] | ' | ' |
Available-for-sale Securities, Fair Value Disclosure | $3.90 | $3.70 |