Fair Value Measurements (Details) - Fair Value, Measurements, Recurring [Member] - USD ($) $ in Thousands	Apr. 01, 2017	Apr. 02, 2016
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	$ 3,366,594	$ 3,493,066
Fair Value, Inputs, Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	333,037	314,571
Fair Value, Inputs, Level 2 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	3,033,557	3,168,518
Fair Value, Inputs, Level 3 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	9,977
Cash And Cash Equivalents [Member] | Money Market Funds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	298,307	232,698
Cash And Cash Equivalents [Member] | financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	158,962
Cash And Cash Equivalents [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	205,322	104,964
Cash And Cash Equivalents [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		1,003
Cash And Cash Equivalents [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	53,982
Cash And Cash Equivalents [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	177,310	98,967
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Money Market Funds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	298,307	232,698
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		0
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	2,998
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Money Market Funds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	158,962
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	205,322	104,964
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		1,003
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	50,984
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	177,310	98,967
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Money Market Funds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		0
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0
Cash And Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	189,835	284,853
Short-Term Investments [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	203,938	460,148
Short-Term Investments [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		61,579
Short-Term Investments [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	76,552	192,293
Short-Term Investments [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	144,811	214,201
Short-Term Investments [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	218,170	210,051
Short-Term Investments [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	1,115,403	1,067,157
Short-Term Investments [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	34,068	35,116
Short-Term Investments [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	217,971	206,470
Short-Term Investments [Member] | Bank Loans [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	154,014	102,015
Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		0
Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	31,732	81,873
Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Bank Loans [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	189,835	284,853
Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	203,938	460,148
Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		61,579
Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	44,820	110,420
Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	144,811	214,201
Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	218,170	210,051
Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	1,115,403	1,067,157
Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	34,068	35,116
Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	217,971	206,470
Short-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Bank Loans [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	154,014	102,015
Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Non-financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		0
Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Government and Agency Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Commercial Mortgage Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Short-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Bank Loans [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Long-Term Investments [Member] | Student loan auction rate securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		9,977
Long-Term Investments [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		7,100
Long-Term Investments [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	1,581	6,563
Long-Term Investments [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	60,099	140,382
Long-Term Investments [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	54,608	56,785
Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Student loan auction rate securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		0
Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		0
Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Student loan auction rate securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		0
Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		7,100
Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	1,581	6,563
Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	60,099	140,382
Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	54,608	56,785
Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Student loan auction rate securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		9,977
Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring		0
Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0	0
Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Fair Value, Net Asset (Liability)	1,661	744
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Fair Value, Net Asset (Liability)	0	0
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 2 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Fair Value, Net Asset (Liability)	1,661	744
Derivative Financial Instruments, Assets [Member] | Fair Value, Inputs, Level 3 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Fair Value, Net Asset (Liability)	$ 0	$ 0