Non-controlling Interest - Distributions Paid or Payable (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Dividends Payable [Line Items]
Distributions paid or payable to or on behalf of non-controlling unitholders	$ 11,460	$ 11,259
Tax and other distributions
Dividends Payable [Line Items]
Distributions paid or payable to or on behalf of non-controlling unitholders	3,547	3,723
Dividend distributions
Dividends Payable [Line Items]
Distributions paid or payable to or on behalf of non-controlling unitholders	$ 7,913	$ 7,536