Financial Instruments (Details 3) (USD $) In Millions	Jun. 30, 2011
Maturities of available-for-sale investments in debt securities
Due in one year or less, Cost	$ 113.4
Due in one year or less, Fair Value	113.4
Due between one and two years, cost	18.0
Due between one and two years, fair value	18.0
Due after ten years, Cost	29.6
Due after ten years, Fair Value	26.8
Maturities of available-for-sale investments in debt securities at cost	161.0
Maturities of available-for-sale investments in debt securities at fair value	$ 158.2

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This item represents debt securities, at cost, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, which are expected to mature after one year and through five years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name FASB Staff Position (FSP)
-Number FAS115-1/124-1
-Paragraph 7
-Footnote 2

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 20
-Subparagraph b

+ Details

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- Definition

This item represents the fair value of debt securities which are expected to mature after one year and through five years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 20
-Subparagraph b

+ Details

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- Definition

This item represents debt securities, at cost, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, which are expected to mature after ten years from the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References

+ Details

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- Definition

This item represents the fair value of debt securities which are expected to mature after ten years from the balance sheet date which are categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 20
-Subparagraph d

+ Details

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- Definition

This item represents the total of all debt securities grouped by maturity dates, at cost, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, which are classified neither as held-to-maturity nor trading securities.

+ References

+ Details

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- Definition

This item represents the total of all debt securities grouped by maturity dates, at fair value, which are categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 20

+ Details

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- Definition

This item represents debt securities, at cost, net of adjustments made for accretion, amortization, other-than-temporary impairments, and hedging, if any, which are expected to mature within one year of the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References

+ Details

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- Definition

This item represents the fair value of debt securities which are expected to mature within one year of the balance sheet date and which are categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 115
-Paragraph 20
-Subparagraph a

+ Details

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