XML 51 R37.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Investments (Tables) | 12 Months Ended
--- | ---
Mar. 31, 2018
Investments [Abstract] |
Summary of Available-for-Sale Securities | The following is a summary of available-for-sale securities at March 31, 2018 (amounts in millions):
| Available-for-sale Securities
| Adjusted Cost |  | Gross Unrealized Gains |  | Gross Unrealized Losses |  | Estimated Fair Value
Government agency bonds | $ | 723.2 |  |  | $ | — |  |  | $ | — |  |  | $ | 723.2 |
Municipal bonds - taxable | 14.9 |  |  | — |  |  | — |  |  | 14.9 |
Time deposits | 11.5 |  |  | — |  |  | — |  |  | 11.5 |
Corporate bonds and debt | 542.9 |  |  | — |  |  | — |  |  | 542.9 |
Marketable equity securities | 0.7 |  |  | 2.1 |  |  | — |  |  | 2.8 |
Total | $ | 1,293.2 |  |  | $ | 2.1 |  |  | $ | — |  |  | $ | 1,295.3 |
The following is a summary of available-for-sale securities at March 31, 2017 (amounts in millions):
| Available-for-sale Securities
| Adjusted Cost |  | Gross Unrealized Gains |  | Gross Unrealized Losses |  | Estimated Fair Value
Government agency bonds | $ | 227.1 |  |  | $ | — |  |  | $ | (0.2 | ) |  | $ | 226.9 |
Municipal bonds - tax exempt | 55.3 |  |  | — |  |  | — |  |  | 55.3 |
Municipal bonds - taxable | 10.0 |  |  | — |  |  | — |  |  | 10.0 |
Corporate bonds and debt | 207.9 |  |  | 0.1 |  |  | (0.2 | ) |  | 207.8 |
Marketable equity securities | 0.7 |  |  | 0.9 |  |  | — |  |  | 1.6 |
Total | $ | 501.0 |  |  | $ | 1.0 |  |  | $ | (0.4 | ) |  | $ | 501.6 |
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value | The following table show all investments in an unrealized loss position for which an other-than-temporary impairment has not been recognized and the related gross unrealized losses and fair value, aggregated by investment category and the length of time that the individual securities have been in a continuous unrealized loss position during the year ended March 31, 2017 (amounts in millions):
| March 31, 2017
| Less than 12 Months |  | 12 Months or Greater |  | Total
| Fair Value |  | Unrealized Loss |  | Fair Value |  | Unrealized Loss |  | Fair Value |  | Unrealized Loss
Government agency bonds | $ | 196.9 |  |  | $ | (0.2 | ) |  | $ | — |  |  | $ | — |  |  | $ | 196.9 |  |  | $ | (0.2 | )
Municipal bonds - tax exempt | 55.3 |  |  | — |  |  | — |  |  | — |  |  | 55.3 |  |  | — |
Corporate bonds and debt | 132.8 |  |  | (0.2 | ) |  | — |  |  | — |  |  | 132.8 |  |  | (0.2 | )
Total | $ | 385.0 |  |  | $ | (0.4 | ) |  | $ | — |  |  | $ | — |  |  | $ | 385.0 |  |  | $ | (0.4 | )
Summary of Amortized Cost and Estimated Fair Value of Available-for-Sale Securities, by Maturity | The amortized cost and estimated fair value of the available-for-sale securities at March 31, 2018, by contractual maturity, excluding marketable equity securities of $2.8 million, which have no contractual maturity, are shown below (amounts in millions). Expected maturities can differ from contractual maturities because the issuers of the securities may have the right to prepay obligations without prepayment penalties, and the Company views its available-for-sale securities as available for current operations.
| Adjusted Cost |  | Gross Unrealized Gains |  | Gross Unrealized Losses |  | Estimated Fair Value
Available-for-sale |  |  |  |  |  |  |
Due in one year or less | $ | 246.5 |  |  | $ | — |  |  | $ | — |  |  | $ | 246.5 |
Due after one year and through five years | 1,046.0 |  |  | — |  |  | — |  |  | 1,046.0 |
Due after five years and through ten years | — |  |  | — |  |  | — |  |  | — |
Due after ten years | — |  |  | — |  |  | — |  |  | — |
Total | $ | 1,292.5 |  |  | $ | — |  |  | $ | — |  |  | $ | 1,292.5 |
The amortized cost and estimated fair value of the available-for-sale securities at March 31, 2017, by maturity, excluding marketable equity securities of $1.6 million, which have no contractual maturity, are shown below (amounts in millions).
| Adjusted Cost |  | Gross Unrealized Gains |  | Gross Unrealized Losses |  | Estimated Fair Value
Available-for-sale |  |  |  |  |  |  |
Due in one year or less | $ | 342.7 |  |  | $ | — |  |  | $ | (0.2 | ) |  | $ | 342.5 |
Due after one year and through five years | 157.6 |  |  | 0.1 |  |  | (0.2 | ) |  | 157.5 |
Due after five years and through ten years | — |  |  | — |  |  | — |  |  | — |
Due after ten years | — |  |  | — |  |  | — |  |  | — |
Total | $ | 500.3 |  |  | $ | 0.1 |  |  | $ | (0.4 | ) |  | $ | 500.0 |

X
- Definition Tabular disclosure of fair value of investments in debt and equity securities in an unrealized loss position categorized neither as held-to-maturity nor trading securities. + References No definition available. + Details
Name: | us-gaap_AvailableForSaleSecuritiesContinuousUnrealizedLossPositionFairValueTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of available-for-sale securities which includes, but is not limited to, changes in the cost basis and fair value, fair value and gross unrealized gain (loss), fair values by type of security, contractual maturity and classification, amortized cost basis, contracts to acquire securities to be accounted for as available-for-sale, debt maturities, transfers to trading, change in net unrealized holding gain (loss) net of tax, continuous unrealized loss position fair value, aggregate losses qualitative disclosures, other than temporary impairment (OTTI) losses or other disclosures related to available for sale securities. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=75019621&loc=d3e62557-112803 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27337-111563 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27198-111563 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 320 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=75019621&loc=d3e62586-112803 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27161-111563 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 9 -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27357-111563 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 320 -SubTopic 10 -Section 50 -Paragraph 6 -URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27290-111563 + Details
Name: | us-gaap_AvailableForSaleSecuritiesTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_InvestmentsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of maturities of an entity's investments as well as any other information pertinent to the investments. + References No definition available. + Details
Name: | us-gaap_InvestmentsClassifiedByContractualMaturityDateTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration