Real Estate Pacific Ridge & Gateway Marketplace Financial Results (Details) - USD ($) $ in Thousands	3 Months Ended								6 Months Ended	8 Months Ended	12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Real Estate [Line Items]
Total revenue	$ 82,605	$ 82,507	$ 85,023	$ 80,732	$ 81,746	$ 82,339	$ 77,106	$ 73,792		$ 12,650	$ 330,867	$ 314,983	$ 295,088
Operating Expenses										16,320	251,332	221,337	197,147
Operating income (loss)	22,091	27,275	17,249	12,920	23,792	26,477	20,048	23,329		(3,670)	79,535	93,646	97,941
Net income	$ 9,209	$ 14,271	$ 4,413	$ (691)	$ 9,731	$ 12,505	$ 7,588	$ 10,308		(3,670)	$ 27,202	$ 40,132	$ 45,637
Pacific Ridge Apartments
Real Estate [Line Items]
Total revenue										10,983
Operating Expenses										15,238
Operating income (loss)										(4,255)
Net income										$ (4,255)
Gateway Marketplace
Real Estate [Line Items]
Total revenue									$ 1,667
Operating Expenses									1,082
Operating income (loss)									585
Net income									$ 585