Noncontrolling interests (Details) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Noncontrolling interests
Payments to Noncontrolling Interests	$ 48,225	$ 32,253	$ 22,361
Noncontrolling Interests
Noncontrolling interests
Number of real estate properties subject to ownership from noncontrolling interest	36
Payments to Noncontrolling Interests	$ 48,200	$ 30,700

Amount of cash outflow to a noncontrolling interest. Includes, but not limited to, reduction of noncontrolling interest ownership. Excludes dividends paid to the noncontrolling interest.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-URI http://asc.fasb.org/extlink&oid=118932676&loc=d3e3291-108585

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