Segment Reporting and Revenue - Reconciliation of Operating Profit (Loss) from Segments to Consolidated (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	$ 268,319	$ 190,995
Cost of revenue	225,961	178,116
Gross profit	42,358	12,879
Operating expenses	76,871	70,309
Interest income	159	1,103
Interest expense	(1,338)	(2,444)
Other income (expense), net	(92)	(1,346)
Net loss	(35,784)	(60,117)
Operating Segments | Real estate services
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	168,609	108,636
Cost of revenue	128,216	93,562
Gross profit	40,393	15,074
Operating Segments | Properties
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	92,726	79,098
Cost of revenue	91,130	79,299
Gross profit	1,596	(201)
Other revenue
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	9,357	4,250
Cost of revenue	8,988	6,244
Gross profit	369	(1,994)
Intercompany eliminations
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Cost of revenue	(2,373)	(989)
Gross profit	0	0
Brokerage revenue | Operating Segments | Real estate services
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	156,447	102,351
Partner revenue | Operating Segments | Real estate services
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Revenue	$ 12,162	$ 6,285