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Affiliate Equity - Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Affiliate Equity
Distributions paid to affiliate partners	$ 347.9	$ 370.5	$ 352.2
Payments to acquire interest in affiliates	146.0	120.0	174.7
Issuance of interest in affiliates	10.5	6.3	$ 9.0
Other Assets
Affiliate Equity
Due from affiliates	14.8	16.2
Other Liabilities
Affiliate Equity
Due to affiliates	$ 19.8	$ 36.2
Minimum
Affiliate Equity
Affiliate equity, conditional right to put interest, period	5 years
Maximum
Affiliate Equity
Affiliate equity, conditional right to put interest, period	15 years

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