v2.4.0.8

2.125% Junior subordinated convertible debentures (Details) (USD $) | 3 Months Ended | 6 Months Ended |  | 3 Months Ended | 6 Months Ended |  | 6 Months Ended
--- | --- | --- | --- | --- | --- | --- | ---
Sep. 30, 2014 | Sep. 30, 2014 | Sep. 30, 2013 | Mar. 31, 2014 | Sep. 30, 2014 Junior subordinated convertible debentures due 2037 [Member] | Sep. 30, 2013 Junior subordinated convertible debentures due 2037 [Member] | Sep. 30, 2014 Junior subordinated convertible debentures due 2037 [Member] | Mar. 31, 2014 Junior subordinated convertible debentures due 2037 [Member] | Sep. 30, 2014 Minimum [Member] Junior subordinated convertible debentures due 2037 [Member] | Sep. 30, 2014 Maximum [Member] Junior subordinated convertible debentures due 2037 [Member]
Debt Instrument [Line Items] |  |  |  |  |  |  |  |  |  |
Principal amount of junior subordinated convertible debentures |  |  |  |  | $ 1,150,000,000.00 |  | $ 1,150,000,000.00 |  |  |
Interest rate of junior subordinated convertible debentures |  |  |  |  | 2.125% |  | 2.125% |  |  |
Due date of junior subordinated convertible debentures |  |  |  |  |  |  | Dec. 15, 2037 |  |  |
Conversion rate, in shares, of junior subordinated convertible debt (in shares per $1,000) |  |  |  |  |  |  | 29.2783 |  |  |
Principal amount of junior subordinated convertible debentures used as conversion unit |  |  |  |  |  |  | 1,000 |  |  |
Convertible Debt Instrument Initial Conversion Price Per Share |  |  |  |  | $ 34.16 |  | $ 34.16 |  |  |
Debt Instrument, Convertible, Conversion Ratio |  |  |  |  |  |  | 39.2544 |  |  |
Debt Instrument, Convertible, Conversion Price |  |  |  |  | $ 25.47 |  | $ 25.47 |  |  |
Long-term Debt, Contingent Payment of Interest, Percentage |  |  |  |  |  |  | 0.50% |  | 0.25% | 0.50%
Debt Instrument, Convertible, Trading Price |  |  |  |  |  |  |  |  | $ 40 | $ 150
Carrying value of equity component of the debentures that were bifurcated into a liability and equity component |  |  |  |  | 822,400,000 |  | 822,400,000 | 822,400,000 |  |
Estimated fair value of liability component of debentures at issuance date |  |  |  |  | 327,600,000 |  | 327,600,000 |  |  |
Debt discount of estimated fair value of liability component of debentures |  |  |  |  | 822,400,000 |  | 822,400,000 |  |  |
Amount of unamortized debt discount of debentures |  |  |  |  | 772,400,000 |  | 772,400,000 | 777,200,000 |  |
Carrying value of debentures | 376,729,000 | 376,729,000 |  | 371,873,000 |  |  |  |  |  |
Remaining period, in years, over which unamortized debt discount will be recognized as non-cash interest expense (in years) |  |  |  |  |  |  | 23 years 3 months |  |  |
Amortization of Debt Discount (Premium) | 2,400,000 | 4,810,000 | 4,396,000 |  |  | 2,200,000 |  |  |  |
Recognized amount of interest expense related to debentures |  |  |  |  | $ 6,100,000 | $ 6,100,000 | $ 12,200,000 |  |  |

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- Definition The amount of debt discount from estimated fair value of the liability component of the debentures at the issuance date. + References No definition available. + Details
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- Definition The principal amount of convertible debt instrument that is used as the conversion unit to determine the number of shares the holder of the debt instrument can convert the debt into. + References No definition available. + Details
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- Definition The initial ratio applied to the debt for purposes of determining the number of shares of the equity security into which the debt will be converted. + References No definition available. + Details
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- Definition This element represents the portion of the balance sheet assertion valued at fair value by the entity whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission. Fair value of junior subordinated convertible debenture at the balance sheet date. + References No definition available. + Details
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- Definition Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.8) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 03 -Paragraph 8 -Article 5 + Details
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- Definition The portion of the carrying value of convertible subordinated debt as of the balance sheet date that is scheduled to be repaid after one year or beyond the normal operating cycle if longer. This form of debt can be exchanged for a specified amount of another security, typically the entity's common stock, at the option of the issuer or the holder, and places a lender in a lien position behind debt having a higher priority of repayment in liquidation of the entity's assets. + 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 210.5-02.22) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 + Details
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- Definition The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031897-161870 + Details
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- Definition The price per share of the conversion feature embedded in the debt instrument. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870 + Details
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- Definition Remaining amortization period for discount on the liability component of convertible debt which may be settled in cash upon conversion, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 20 -Section 50 -Paragraph 5 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870 + Details
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- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 22 -Article 5 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 1A -URI http://asc.fasb.org/extlink&oid=6451184&loc=d3e28541-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=34725769&loc=d3e28878-108400 + Details
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