Financial Instruments And Fair Value (Policy)	9 Months Ended
Jan. 27, 2012
Financial Instruments And Fair Value [Abstract]
Fair Value Measurement and Impairments	The accounting guidance for fair value measurements provides a framework for measuring fair value on either a recurring or nonrecurring basis whereby the inputs used in valuation techniques are assigned a hierarchical level. The following are the three levels of inputs to measure fair value: Level 1: Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. Level 2: Inputs that reflect quoted prices for identical assets or liabilities in less active markets; quoted prices for similar assets or liabilities in active markets; inputs other than quoted prices that are observable for the assets or liabilities; or inputs that are derived principally from or corroborated by observable market data by correlation or other means. Level 3: Unobservable inputs that reflect our own assumptions incorporated in valuation techniques used to measure fair value. These assumptions are required to be consistent with market participant assumptions that are reasonably available. We consider an active market to be one in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an on-going basis, and consider an inactive market to be one in which there are infrequent or few transactions for the asset or liability, the prices are not current, or price quotations vary substantially either over time or among market makers. Where appropriate, our own or the counterparty's non-performance risk is considered in measuring the fair values of liabilities and assets, respectively.

The accounting guidance for fair value measurements provides a framework for measuring fair value on either a recurring or nonrecurring basis whereby the inputs used in valuation techniques are assigned a hierarchical level. The following are the three levels of inputs to measure fair value:

Level 1: Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets.

Level 2: Inputs that reflect quoted prices for identical assets or liabilities in less active markets; quoted prices for similar assets or liabilities in active markets; inputs other than quoted prices that are observable for the assets or liabilities; or inputs that are derived principally from or corroborated by observable market data by correlation or other means.

Level 3: Unobservable inputs that reflect our own assumptions incorporated in valuation techniques used to measure fair value. These assumptions are required to be consistent with market participant assumptions that are reasonably available.

We consider an active market to be one in which transactions for the asset or liability occur with sufficient frequency and volume to provide pricing information on an on-going basis, and consider an inactive market to be one in which there are infrequent or few transactions for the asset or liability, the prices are not current, or price quotations vary substantially either over time or among market makers. Where appropriate, our own or the counterparty's non-performance risk is considered in measuring the fair values of liabilities and assets, respectively.