Amount of income (loss) for proportionate share of equity method investee's income (loss).

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Name:	us-gaap_IncomeLossFromEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Equity method and other investments - Additional Information (Details) - USD ($) $ in Thousands			3 Months Ended		9 Months Ended
	Dec. 01, 2019	Aug. 01, 2019	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Noncontrolling Interest [Line Items]
Equity investment income			$ 3,936	$ (3,824)	$ 11,158	$ 6,126
Partnership Capital Contribution Scheduled Date		Aug. 01, 2019
Valuation Adjustment					$ 1,938	$ 0
Minimum
Noncontrolling Interest [Line Items]
Current economic interest in the APAC JV, Owned by the Parent Company			30.00%		30.00%
Maximum
Noncontrolling Interest [Line Items]
Current economic interest in the APAC JV, Owned by the Parent Company			50.00%		50.00%
Forecast
Noncontrolling Interest [Line Items]
Partnership Capital Contribution Deferred Date	Dec. 01, 2019