Segment Information - Narrative (Details) $ in Thousands	3 Months Ended	9 Months Ended
	Sep. 30, 2019 USD ($) segment	Sep. 30, 2019 USD ($) segment	Dec. 31, 2018 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment	3	3
Other assets, net	$ 301,760	$ 301,760	$ 264,994
Third-Party Real Estate Services Segment
Segment Reporting Information [Line Items]
Other assets, net	$ 33,300	$ 33,300	$ 38,600