A roll forward schedule of the summary of accumulated other comprehensive income (loss) components, net of tax.

No definition available.

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- Definition

Accumulated change in equity from transactions and other events and circumstances from non-owner sources, net of tax effect, at period end. Excludes Net Income (Loss), and accumulated changes in equity from transactions resulting from investments by owners and distributions to owners. Includes foreign currency translation items, certain pension adjustments, unrealized gains and losses on certain investments in debt and equity securities, other than temporary impairment (OTTI) losses related to factors other than credit losses on available-for-sale and held-to-maturity debt securities that an entity does not intend to sell and it is not more likely than not that the entity will be required to sell before recovery of the amortized cost basis, as well as changes in the fair value of derivatives related to the effective portion of a designated cash flow hedge.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 11
-URI http://asc.fasb.org/extlink&oid=84228862&loc=d3e637-108580

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-Publisher FASB
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-Publisher FASB
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-Topic 220
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-Section 45
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-URI http://asc.fasb.org/extlink&oid=84228862&loc=SL7669686-108580

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- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
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- Definition

Amount after tax and reclassification adjustments, of increase (decrease) in accumulated gain (loss) from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's increase (decrease) in deferred hedging gain (loss).

+ References

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- Definition

Amount after tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 830
-SubTopic 30
-Section 45
-Paragraph 20
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- Definition

Amount after tax and reclassification adjustments of other comprehensive income (loss).

+ References

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- Definition

Amount after tax, before reclassification adjustments, of unrealized holding gain (loss) on available-for-sale securities.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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Comprehensive Income (Loss) (Accumulated other comprehensive income (loss) components of net of tax) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Accumulated Other Comprehensive Income (Loss) Components, Net of Tax [Roll Forward]
Balance as of March 31, 2017			$ (51,236)
Foreign currency translation	$ 12,767	$ (1,704)	21,034	$ (1,982)
Unrealized net gain on investments	10,057	20,013	16,968	39,401
Change in fair value of cash flow hedges	740	1,926	1,700	3,216
Amount reclassified from AOCI			2,618	5,107
Other comprehensive income (loss)	148,203	$ 196,710	290,548	$ 364,283
Balance as of September 30, 2017	(11,534)		(11,534)
Foreign Currency Translation [Member]
Accumulated Other Comprehensive Income (Loss) Components, Net of Tax [Roll Forward]
Balance as of March 31, 2017			(69,505)
Foreign currency translation			21,034
Unrealized net gain on investments
Change in fair value of cash flow hedges
Amount reclassified from AOCI
Other comprehensive income (loss)			21,034
Balance as of September 30, 2017	(48,471)		(48,471)
Unrealized Net Gain on Investments [Member]
Accumulated Other Comprehensive Income (Loss) Components, Net of Tax [Roll Forward]
Balance as of March 31, 2017			23,099
Foreign currency translation
Unrealized net gain on investments			16,968
Change in fair value of cash flow hedges
Amount reclassified from AOCI
Other comprehensive income (loss)			16,968
Balance as of September 30, 2017	40,067		40,067
Fair Market Value of Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income (Loss) Components, Net of Tax [Roll Forward]
Balance as of March 31, 2017			(3,059)
Foreign currency translation
Unrealized net gain on investments
Change in fair value of cash flow hedges			4,318
Amount reclassified from AOCI			(2,618)
Other comprehensive income (loss)			1,700
Balance as of September 30, 2017	(1,359)		(1,359)
Postretirement Benefit Obligation Gain [Member]
Accumulated Other Comprehensive Income (Loss) Components, Net of Tax [Roll Forward]
Balance as of March 31, 2017			(1,771)
Foreign currency translation
Unrealized net gain on investments
Change in fair value of cash flow hedges
Amount reclassified from AOCI
Other comprehensive income (loss)
Balance as of September 30, 2017	(1,771)		(1,771)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income (Loss) Components, Net of Tax [Roll Forward]
Balance as of March 31, 2017			(51,236)
Foreign currency translation			21,034
Unrealized net gain on investments			16,968
Change in fair value of cash flow hedges			4,318
Amount reclassified from AOCI			(2,618)
Other comprehensive income (loss)			39,702
Balance as of September 30, 2017	$ (11,534)		$ (11,534)