Fair Value Hierarchy of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Millions | May 26, 2017 | Feb. 24, 2017 |
Assets, Fair Value Disclosure [Abstract] | | |
Cash and Cash Equivalents, Fair Value Disclosure | $ 143.9 | $ 197.1 |
Restricted Cash and Cash Equivalents | 2.5 | 2.5 |
Assets, Fair Value Disclosure | 188.7 | 280 |
Liabilities, Fair Value Disclosure [Abstract] | | |
Foreign exchange forward contracts, Liability, Fair Value Disclosure | (0.5) | (0.9) |
Liabilities, Fair Value Disclosure | (0.5) | (0.9) |
Corporate Debt Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 18.5 | 33.6 |
US Government Agencies Debt Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 10.1 | 18.6 |
Asset-backed Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 5.4 | 3.7 |
US Government-sponsored Enterprises Debt Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 2.3 | 2.4 |
Municipal Bonds [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 1 | 15.1 |
Foreign Exchange Contract [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Foreign Currency Contract, Asset, Fair Value Disclosure | 1.5 | 3.5 |
Auction Rate Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 3.5 | 3.5 |
Fair Value, Inputs, Level 1 [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Cash and Cash Equivalents, Fair Value Disclosure | 143.9 | 197.1 |
Restricted Cash and Cash Equivalents | 2.5 | 2.5 |
Assets, Fair Value Disclosure | 148.7 | 202 |
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 | 2.3 | 2.4 |
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] | | |
Foreign Currency Contract, Asset, 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 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 | 36.5 | 74.5 |
Liabilities, Fair Value Disclosure [Abstract] | | |
Foreign exchange forward contracts, Liability, Fair Value Disclosure | (0.5) | (0.9) |
Liabilities, Fair Value Disclosure | (0.5) | (0.9) |
Fair Value, Inputs, Level 2 [Member] | Corporate Debt Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 18.5 | 33.6 |
Fair Value, Inputs, Level 2 [Member] | US Government Agencies Debt Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 10.1 | 18.6 |
Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Available-for-sale Securities, Fair Value Disclosure | 5.4 | 3.7 |
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 | 15.1 |
Fair Value, Inputs, Level 2 [Member] | Foreign Exchange Contract [Member] | | |
Assets, Fair Value Disclosure [Abstract] | | |
Foreign Currency Contract, Asset, Fair Value Disclosure | 1.5 | 3.5 |
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 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 | 3.5 | 3.5 |
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] | 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] | | |
Foreign Currency Contract, Asset, 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 | $ 3.5 | $ 3.5 |