Revenue Recognition (Narrative) (Details)	3 Months Ended	6 Months Ended
Sep. 30, 2020 USD ($)	Sep. 30, 2020 USD ($)
Revenue from Contract with Customer [Line Items]
Percentage of deferred revenue balance expected to be recognized in one year or less		92.00%
Deferred revenue recognized		$ 202,837,000
Customer contracts, impairment loss	$ 0	0
Remaining performance obligation	$ 1,500,164,000	$ 1,500,164,000
Over Time [Member]
Revenue from Contract with Customer [Line Items]
Percentage of revenue recognized	97.00%	94.00%
Point in Time [Member]
Revenue from Contract with Customer [Line Items]
Percentage of revenue recognized	3.00%	6.00%
Prepaid and Other Current Assets [Member] \| Obtain Contract [Member]
Revenue from Contract with Customer [Line Items]
Capitalized contract costs, current	$ 4,505,000	$ 4,505,000
Prepaid and Other Current Assets [Member] \| Fulfill Contract [Member]
Revenue from Contract with Customer [Line Items]
Capitalized contract costs, current	5,425,000	5,425,000
Other Noncurrent Assets [Member] \| Obtain Contract [Member]
Revenue from Contract with Customer [Line Items]
Capitalized contract costs, noncurrent	16,131,000	16,131,000
Other Noncurrent Assets [Member] \| Fulfill Contract [Member]
Revenue from Contract with Customer [Line Items]
Capitalized contract costs, noncurrent	$ 10,250,000	$ 10,250,000

Percentage of Deferred Revenue Balances Expected to be Recognized in One Year or Less

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Percentage of Revenue Recognized

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Revenue from Contract with Customer [Line Items]

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- Definition

Amount of impairment loss for asset recognized from cost incurred to obtain or fulfill contract with customer.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

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Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer; classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

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Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer; classified as noncurrent.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 340
-SubTopic 40
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=68051541&loc=SL49131252-203054

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Amount of revenue recognized that was previously included in balance of obligation to transfer good or service to customer for which consideration from customer has been received or is due.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 8
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130549-203045

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Amount of transaction price allocated to performance obligation that has not been recognized as revenue.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 13
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=121604090&loc=SL49130556-203045

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