Cash Equivalents, and Investments, Narrative (Details) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2015 USD ($) Investment	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) Investment	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($) Investment
Cash Equivalents and Investments [Abstract]
Total investments in unrealized loss position \| Investment	418		418		437
Available-for-sale securities, other than temporary impairment	$ 0.0	$ 0.0	$ 0.0	$ 1.6
Available-for-sale securities, gross realized gains				165.8
Privately-held investments	92.1		92.1		$ 89.9
Privately held investments at fair value	50.3		50.3		$ 47.5
Unrealized gain (loss) on privately-held debt securities	$ 0.0	$ 10.0	$ 0.0	$ 10.0

cash equivalents and investments.

No definition available.

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- Definition

Privately-held Investments

+ References

No definition available.

+ Details

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- Definition

Privately held investments at fair value

+ References

No definition available.

+ Details

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- Definition

This item represents the gross profit realized on the sale of debt or equity securities categorized neither as held-to-maturity nor trading securities.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 9

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27357-111563

+ Details

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- Definition

Number of investment positions in available-for-sale investments in a continuous unrealized loss position for which an other-than-temporary impairment (OTTI) has not been recognized in the income statement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 50

-Paragraph 6

-Subparagraph (b)(3)

-URI http://asc.fasb.org/extlink&oid=27724398&loc=d3e27290-111563

+ Details

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- Definition

The amount of other than temporary impairment losses on investments in debt and equity securities categorized as Available-for-sale which have been recognized in earnings during the period. Such impairment losses consist of other than temporary impairments (OTTI) on equity securities, credit losses on investments in debt securities, and when the entity intends to sell an impaired debt security or it is more likely than not that the entity will be required to sell the impaired debt security before recovery of its amortized cost basis.

+ References

Reference 1: 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=27724398&loc=d3e27161-111563

+ Details

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- Definition

The aggregate net change in the difference between the fair value and the carrying value, or in the comparative fair values, of marketable securities categorized as trading held at each balance sheet date, that was included in earnings for the period, which may have arisen from (a) securities classified as trading, (b) the unrealized holding gain (loss) on held-to-maturity securities transferred to the trading security category, and (c) the cumulative unrealized gain (loss) which was included in other comprehensive income (a separate component of shareholders' equity) on available-for-sale securities transferred to trading securities during the period and/or any unrealized gains or losses on investments that are separately or otherwise not categorized as trading or available-for-sale.

+ References

No definition available.

+ Details

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