Condensed Consolidated and Combined Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Loss [Abstract]
NET INCOME (LOSS)	$ (40,263)	$ (3,328)	$ 7,912	$ 24,920
OTHER COMPREHENSIVE LOSS:
Change in fair value of derivative financial instruments	(5,283)	(16,256)	(39,211)	(26,952)
Reclassification of net (income) loss on derivative financial instruments from accumulated other comprehensive loss into interest expense	3,156	(951)	4,314	(1,790)
Other comprehensive loss	(2,127)	(17,207)	(34,897)	(28,742)
COMPREHENSIVE LOSS	(42,390)	(20,535)	(26,985)	(3,822)
Net (income) loss attributable to redeemable noncontrolling interests	3,483	288	(1,767)	(3,099)
Other comprehensive loss attributable to redeemable noncontrolling interests	182	1,503	3,755	2,886
COMPREHENSIVE LOSS ATTRIBUTABLE TO JBG SMITH PROPERTIES	$ (38,725)	$ (18,744)	$ (24,997)	$ (4,035)