Fair Value Hierarchy of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) (USD $) | Nov. 28, 2014 | Feb. 28, 2014 |
In Millions, unless otherwise specified |
Assets, Fair Value Disclosure [Abstract] | | |
Restricted Cash and Cash Equivalents | $2.50 | $9 |
Fair Value, Measurements, Recurring [Member] | Asset-backed Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 10.1 | 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 | 128.8 | 201.8 |
Foreign Currency Contract, Asset, Fair Value Disclosure | 0 | 0 |
Assets, Fair Value Disclosure | 135.1 | 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 | 3.8 | 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 | 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 | 11.3 | 0.3 |
Assets, Fair Value Disclosure | 98.7 | 115.7 |
Liabilities, Fair Value Disclosure [Abstract] | | |
Foreign Currency Contracts, Liability, Fair Value Disclosure | -1.4 | -3.2 |
Liabilities, Fair Value Disclosure | -1.4 | -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 | 22.4 | 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 | 46.2 | 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 | 10.1 | 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 | 3.1 | 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 | 1.8 | 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 | 3.8 | 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 | 9.6 | 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 | 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 | 9.6 | 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 | 128.8 | 201.8 |
Restricted Cash and Cash Equivalents | 2.5 | 9 |
Foreign Currency Contract, Asset, Fair Value Disclosure | 11.3 | 0.3 |
Assets, Fair Value Disclosure | 243.4 | 343.9 |
Liabilities, Fair Value Disclosure [Abstract] | | |
Foreign Currency Contracts, Liability, Fair Value Disclosure | -1.4 | -3.2 |
Liabilities, Fair Value Disclosure | -1.4 | -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 | 22.4 | 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 | 46.2 | 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 | 3.8 | 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 | 3.1 | 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 | 1.8 | 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 | 9.6 | 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 | $3.80 | $3.70 |