Fair Value Measurements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2016	Jan. 02, 2016	Dec. 31, 2016	Jan. 02, 2016	Oct. 01, 2016	Apr. 02, 2016	Sep. 26, 2015	Mar. 28, 2015
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value	$ 10,227	$ 10,111	$ 10,227	$ 10,111	$ 10,160	$ 9,977	$ 10,413	$ 10,312
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset, Gain (Loss) Included in Other Comprehensive Income (Loss)	67	$ (302)	250	$ (201)
Fair Value, Measurements, Recurring [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	3,374,965		3,374,965			3,493,066
Liabilities, Fair Value Disclosure, Recurring	1,753		1,753
Fair Value, Net Asset (Liability)	3,373,212		3,373,212
Fair Value, Measurements, Recurring [Member] | Derivative Financial Instruments, Liabilities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	1,753		1,753
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	421,057		421,057			314,571
Liabilities, Fair Value Disclosure, Recurring	0		0
Fair Value, Net Asset (Liability)	421,057		421,057
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Derivative Financial Instruments, Liabilities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	2,943,681		2,943,681			3,168,518
Liabilities, Fair Value Disclosure, Recurring	1,753		1,753
Fair Value, Net Asset (Liability)	2,941,928		2,941,928
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Financial Instruments, Liabilities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	1,753		1,753
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	10,227		10,227			9,977
Liabilities, Fair Value Disclosure, Recurring	0		0
Fair Value, Net Asset (Liability)	10,227		10,227
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Derivative Financial Instruments, Liabilities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Liabilities, Fair Value Disclosure, Recurring	0		0
Fair Value, Measurements, Recurring [Member] | 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	366,460		366,460			232,698
Fair Value, Measurements, Recurring [Member] | 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	299,875		299,875
Fair Value, Measurements, Recurring [Member] | 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	22,689		22,689			104,964
Fair Value, Measurements, Recurring [Member] | 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
Fair Value, Measurements, Recurring [Member] | 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	83,272		83,272
Fair Value, Measurements, Recurring [Member] | 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	4,998		4,998			98,967
Fair Value, Measurements, Recurring [Member] | 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	366,460		366,460			232,698
Fair Value, Measurements, Recurring [Member] | 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		0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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
Fair Value, Measurements, Recurring [Member] | 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	24,990		24,990
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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	299,875		299,875
Fair Value, Measurements, Recurring [Member] | 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	22,689		22,689			104,964
Fair Value, Measurements, Recurring [Member] | 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
Fair Value, Measurements, Recurring [Member] | 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	58,282		58,282
Fair Value, Measurements, Recurring [Member] | 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	4,998		4,998			98,967
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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		0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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
Fair Value, Measurements, Recurring [Member] | 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		0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Financial institution securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	174,997		174,997			284,853
Fair Value, Measurements, Recurring [Member] | 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	272,956		272,956			460,148
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	50,067		50,067			61,579
Fair Value, Measurements, Recurring [Member] | 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	93,176		93,176			192,293
Fair Value, Measurements, Recurring [Member] | 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	89,752		89,752			214,201
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	210,465		210,465			210,051
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	1,141,926		1,141,926			1,067,157
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	33,952		33,952			35,116
Fair Value, Measurements, Recurring [Member] | Short-Term Investments [Member] | Bank Loans [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	131,056		131,056			102,015
Fair Value, Measurements, Recurring [Member] | 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	216,242		216,242			206,470
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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		0			0
Fair Value, Measurements, Recurring [Member] | 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	29,607		29,607			81,873
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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	174,997		174,997			284,853
Fair Value, Measurements, Recurring [Member] | 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	272,956		272,956			460,148
Fair Value, Measurements, Recurring [Member] | 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	50,067		50,067			61,579
Fair Value, Measurements, Recurring [Member] | 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	63,569		63,569			110,420
Fair Value, Measurements, Recurring [Member] | 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	89,752		89,752			214,201
Fair Value, Measurements, Recurring [Member] | 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	210,465		210,465			210,051
Fair Value, Measurements, Recurring [Member] | 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	1,141,926		1,141,926			1,067,157
Fair Value, Measurements, Recurring [Member] | 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	33,952		33,952			35,116
Fair Value, Measurements, Recurring [Member] | 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	131,056		131,056			102,015
Fair Value, Measurements, Recurring [Member] | 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	216,242		216,242			206,470
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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		0			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Auction Rate Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	10,227		10,227			9,977
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Municipal Bonds [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	4,726		4,726			7,100
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Asset-backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	5,388		5,388			6,563
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Mortgage-Backed Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	110,758		110,758			140,382
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Debt Mutual Fund [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	51,983		51,983			56,785
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring						744
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Auction Rate Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | 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		0			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 1 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring						0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Auction Rate Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	0		0			0
Fair Value, Measurements, Recurring [Member] | 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	4,726		4,726			7,100
Fair Value, Measurements, Recurring [Member] | 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	5,388		5,388			6,563
Fair Value, Measurements, Recurring [Member] | 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	110,758		110,758			140,382
Fair Value, Measurements, Recurring [Member] | 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	51,983		51,983			56,785
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 2 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring						744
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Auction Rate Securities [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring	10,227		10,227			9,977
Fair Value, Measurements, Recurring [Member] | 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		0			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | 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			0
Fair Value, Measurements, Recurring [Member] | Long-Term Investments [Member] | Fair Value, Inputs, Level 3 [Member] | Derivative Financial Instruments, Assets [Member]
Assets and Liabilities Measured at Fair Value on a Recurring Basis
Assets, Fair Value Disclosure, Recurring						$ 0