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Fair Value Measurements - Quantitative Information (Details) (Discounted cash flow, USD $) In Millions, unless otherwise specified			3 Months Ended							3 Months Ended
	Mar. 31, 2014 Contingent payment arrangements [Member]	Dec. 31, 2013 Contingent payment arrangements [Member]	Mar. 31, 2014 Contingent payment arrangements [Member] Minimum	Mar. 31, 2013 Contingent payment arrangements [Member] Minimum	Mar. 31, 2014 Contingent payment arrangements [Member] Maximum	Mar. 31, 2013 Contingent payment arrangements [Member] Maximum	Mar. 31, 2013 Affiliate equity repurchase obligations [Member]	Mar. 31, 2014 Affiliate equity repurchase obligations [Member]	Dec. 31, 2013 Affiliate equity repurchase obligations [Member]	Mar. 31, 2014 Affiliate equity repurchase obligations [Member] Minimum	Mar. 31, 2014 Affiliate equity repurchase obligations [Member] Maximum
Quantitative information for Level 3 Fair Value Measurements Liabilities
Fair value Liabilities	$ 53.2	$ 50.2						$ 58.3	$ 4.0
Growth rate (as a percent)			3.00%	3.00%	9.00%	11.00%	8.00%			2.00%	11.00%
Discount rate (as a percent)			13.00%	14.00%	17.00%	18.00%	15.00%			14.00%	17.00%

X

- Definition

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

+ References

No definition available.

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- 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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- 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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