v2.4.0.8

Summary of Available for Sale (Details) (USD $) | 6 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2014 | Mar. 31, 2014
Summary of available-for-sale securities [Line Items] |  |
Available-for-sale, adjusted cost | $ 1,643,964,000 | $ 1,677,422,000
Available-for-sale, gross unrealized gains | 2,345,000 | 3,462,000
Available-for-sale, gross unrealized losses | (3,362,000) | (3,990,000)
Available-for-sale, estimated fair value | 1,642,947,000 | 1,676,894,000
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value [Abstract] |  |
Fair Value of Available-for-sale Securities in a Continuous Unrealized Loss Position | 833,300,000 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Aggregate Loss [Abstract] |  |
Aggregate Loss, Available-for-sale Securities in a Continuous Unrealized Loss Position | (3,362,000) |
Government agency bonds [Member] |  |
Summary of available-for-sale securities [Line Items] |  |
Available-for-sale, adjusted cost | 668,639,000 | 684,451,000
Available-for-sale, gross unrealized gains | 129,000 | 114,000
Available-for-sale, gross unrealized losses | (2,560,000) | (3,171,000)
Available-for-sale, estimated fair value | 666,208,000 | 681,394,000
Municipal bonds [Member] |  |
Summary of available-for-sale securities [Line Items] |  |
Available-for-sale, adjusted cost | 41,097,000 | 41,622,000
Available-for-sale, gross unrealized gains | 66,000 | 101,000
Available-for-sale, gross unrealized losses | (2,000) | (14,000)
Available-for-sale, estimated fair value | 41,161,000 | 41,709,000
Auction rate securities [Member] |  |
Summary of available-for-sale securities [Line Items] |  |
Available-for-sale, adjusted cost | 9,825,000 | 9,825,000
Available-for-sale, gross unrealized gains | 0 | 0
Available-for-sale, gross unrealized losses | 0 | 0
Available-for-sale, estimated fair value | 9,825,000 | 9,825,000
Time Deposits [Member] |  |
Summary of available-for-sale securities [Line Items] |  |
Available-for-sale, adjusted cost | 20,160,000 |
Available-for-sale, gross unrealized gains | 0 |
Available-for-sale, gross unrealized losses | 0 |
Available-for-sale, estimated fair value | 20,160,000 |
Corporate bonds and debt [Member] |  |
Summary of available-for-sale securities [Line Items] |  |
Available-for-sale, adjusted cost | 904,243,000 | 941,524,000
Available-for-sale, gross unrealized gains | 2,150,000 | 3,247,000
Available-for-sale, gross unrealized losses | (800,000) | (805,000)
Available-for-sale, estimated fair value | $ 905,593,000 | $ 943,966,000

X
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- Definition This item represents the cost of debt and equity securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.2) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition This item represents the aggregate fair value of investments in debt and equity securities in an unrealized loss position which are categorized neither as held-to-maturity nor trading securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563 + Details
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- Definition Amount of unrealized gain before deducting unrealized loss on investments in debt and equity securities classified as available-for-sale securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27161-111563 + Details
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