Debt - Convertible Debt (Details)	6 Months Ended
Sep. 30, 2020 USD ($) $ / shares
Debt Instrument [Line Items]
Value if converted above par \| $	$ 1,000
2015 Senior Convertible Debt
Debt Instrument [Line Items]
Threshold percentage of stock price trigger	130.00%
Senior Convertible Debt \| 2017 Senior Convertible Debt
Debt Instrument [Line Items]
Conversion Rate	10.5359
Approximate Conversion Price (in dollars per share) \| $ / shares	$ 94.91
Incremental Share Factor	5.2679
Maximum Conversion Rate	15.0136
Value if converted above par \| $	$ 129,500,000
Senior Convertible Debt \| 2015 Senior Convertible Debt
Debt Instrument [Line Items]
Conversion Rate	16.4300
Approximate Conversion Price (in dollars per share) \| $ / shares	$ 60.86
Incremental Share Factor	8.2150
Maximum Conversion Rate	23.0019
Conversion rate, adjusted based on closing stock price	19.7793
Value if converted above par \| $	$ 322,500,000
Junior Convertible Debt \| 2017 Junior Convertible Debt
Debt Instrument [Line Items]
Conversion Rate	10.7240
Approximate Conversion Price (in dollars per share) \| $ / shares	$ 93.25
Incremental Share Factor	5.3621
Maximum Conversion Rate	15.0136
Value if converted above par \| $	$ 105,000,000.0
Common Stock
Debt Instrument [Line Items]
Share price (in dollars per share) \| $ / shares	$ 102.76

Debt Instrument, Convertible, Adjusted Conversion Ratio

No definition available.

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- Definition

The amount of shares of common stock that will be added to the conversion ratio if at the time of conversion the applicable stock price of the Company's common stock exceeds the base conversion price, adjusted for dividends paid since the issuance date.

+ References

No definition available.

+ Details

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- Definition

Debt Instrument, Convertible, Conversion Ratio Maximum Conversion Rate, Adjusted for Paid Dividends

+ References

No definition available.

+ Details

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- Definition

The price per share of the conversion feature embedded in the debt instrument.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031898-161870

+ Details

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- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21521-112644

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 6
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21506-112644

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(5))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Name Accounting Standards Codification
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-Paragraph 3
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- Definition

The amount by which the convertible debt's if-converted value exceeds its principle amount at the balance sheet date, regardless of whether the instrument is currently convertible. This element applies to public companies only.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=109500613&loc=SL6031898-161870

+ Details

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Balance Type:	credit
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- Definition

Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

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- Details

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