Fair Value Hierarchy of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Millions | Nov. 25, 2016 | Feb. 26, 2016 |
Fair Value, Inputs, Level 1 [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Cash and Cash Equivalents, Fair Value Disclosure | $ 139.1 | $ 181.9 |
Restricted Cash and Cash Equivalents | 2.5 | 2.5 |
Assets, Fair Value Disclosure | 143.8 | 192.6 |
Liabilities, Fair Value Disclosure [Abstract] | | |
Foreign exchange forward contracts, Liability, Fair Value Disclosure | 0 | 0 |
Liabilities, Fair Value Disclosure | 0 | 0 |
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, 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, Inputs, Level 1 [Member] | Asset-backed Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
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 | 2.2 | 8.2 |
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, Inputs, Level 1 [Member] | Foreign Exchange Contract [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
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, 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, 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 |
Assets, Fair Value Disclosure | 101.9 | 80.8 |
Liabilities, Fair Value Disclosure [Abstract] | | |
Foreign exchange forward contracts, Liability, Fair Value Disclosure | (2.3) | (3.3) |
Liabilities, Fair Value Disclosure | (2.3) | (3.3) |
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 63.4 | 31.7 |
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 21 | 34.7 |
Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 8.8 | 9.2 |
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, Inputs, Level 2 [Member] | Municipal Bonds [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 1.3 | 0.3 |
Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Contract [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 5 | 1.8 |
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, Inputs, Level 2 [Member] | Canadian Asset Backed Commercial Paper Restructuring Notes [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 2.4 | 3.1 |
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 |
Assets, Fair Value Disclosure | 3.7 | 4.4 |
Liabilities, Fair Value Disclosure [Abstract] | | |
Foreign exchange forward contracts, Liability, Fair Value Disclosure | 0 | 0 |
Liabilities, Fair Value Disclosure | 0 | 0 |
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, 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, Inputs, Level 3 [Member] | Asset-backed Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
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, Inputs, Level 3 [Member] | Municipal Bonds [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Inputs, Level 3 [Member] | Foreign Exchange Contract [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 0 | 0 |
Fair Value, Inputs, Level 3 [Member] | Auction Rate Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 3.7 | 4.4 |
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 |
Estimate of Fair Value, Fair Value Disclosure [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 139.1 | 181.9 |
Restricted Cash and Cash Equivalents | 2.5 | 2.5 |
Assets, Fair Value Disclosure | 249.4 | 277.8 |
Liabilities, Fair Value Disclosure [Abstract] | | |
Foreign exchange forward contracts, Liability, Fair Value Disclosure | (2.3) | (3.3) |
Liabilities, Fair Value Disclosure | (2.3) | (3.3) |
Estimate of Fair Value, Fair Value Disclosure [Member] | Corporate Debt Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 63.4 | 31.7 |
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 | 21 | 34.7 |
Estimate of Fair Value, Fair Value Disclosure [Member] | Asset-backed Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 8.8 | 9.2 |
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 | 2.2 | 8.2 |
Estimate of Fair Value, Fair Value Disclosure [Member] | Municipal Bonds [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 1.3 | 0.3 |
Estimate of Fair Value, Fair Value Disclosure [Member] | Foreign Exchange Contract [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 5 | 1.8 |
Estimate of Fair Value, Fair Value Disclosure [Member] | Auction Rate Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 3.7 | 4.4 |
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 | $ 2.4 | $ 3.1 |