v3.8.0.1

Fair Value of Financial Instruments (Schedule of carrying amounts and fair values) (Details) - USD ($) $ in Thousands	Sep. 30, 2017	Mar. 31, 2017
Carrying Value | 2017 Senior Subordinated Convertible Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for subordinated convertible debentures	$ 1,410,892	$ 1,384,914
Carrying Value | 2015 Senior Subordinated Convertible Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for subordinated convertible debentures	1,285,498	1,261,787
Carrying Value | 2017 Junior Subordinated Convertible Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for subordinated convertible debentures	322,487	262,298
Carrying Value | 2007 Junior Subordinated Convertible Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for subordinated convertible debentures	5,980	49,952
Estimate of Fair Value Measurement | 2017 Senior Subordinated Convertible Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for subordinated convertible debentures	2,520,225	2,106,225
Estimate of Fair Value Measurement | 2015 Senior Subordinated Convertible Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for subordinated convertible debentures	3,005,813	2,481,708
Estimate of Fair Value Measurement | 2017 Junior Subordinated Convertible Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for subordinated convertible debentures	834,665	586,609
Estimate of Fair Value Measurement | 2007 Junior Subordinated Convertible Debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value disclosure for subordinated convertible debentures	$ 63,999	$ 445,142

X

- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13433-108611

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 12
-URI http://asc.fasb.org/extlink&oid=77997519&loc=d3e13476-108611

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- Definition

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+ References

No definition available.

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