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Fair Value Measurements - Schedule of quantitative information (Details) (Discounted cash flow, USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Contingent Payment Arrangements [Member]
Quantitative information for Level 3 Fair Value Measurements Liabilities
Fair value Liabilities	$ 50.2	$ 31.0
Contingent Payment Arrangements [Member] | Minimum [Member]
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)	3.00%	6.00%
Discount rate (as a percent)	14.00%	14.00%
Contingent Payment Arrangements [Member] | Maximum [Member]
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)	11.00%	12.00%
Discount rate (as a percent)	18.00%	18.00%
Affiliate equity repurchase obligations [Member]
Quantitative information for Level 3 Fair Value Measurements Liabilities
Fair value Liabilities	$ 4.0	$ 9.4
Growth rate (as a percent)	8.00%
Discount rate (as a percent)	15.00%
Affiliate equity repurchase obligations [Member] | Minimum [Member]
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)		(10.00%)
Discount rate (as a percent)		15.00%
Affiliate equity repurchase obligations [Member] | Maximum [Member]
Quantitative information for Level 3 Fair Value Measurements Liabilities
Growth rate (as a percent)		17.00%
Discount rate (as a percent)		24.00%

X

- Definition

Represents percentage of assumed growth rates, used as an input to measure fair value.

+ References

No definition available.

+ Details

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X

- Definition

Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (bbb)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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- Details

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X

- Definition

Fair value of financial and nonfinancial obligations.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=25499696&loc=d3e19207-110258

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