Consolidated and Combined Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
NET INCOME (LOSS)	$ (3,328)	$ 24,023	$ 24,920	$ 19,237
Other Comprehensive Income (Loss) [Abstract]
Change in fair value of derivative financial instruments	(16,256)	5,215	(26,952)	19,311
Reclassification of net (income) loss on derivative financial instruments from accumulated other comprehensive income into interest expense	(951)	414	(1,790)	1,449
Other comprehensive income (loss)	17,207	(5,629)	28,742	(20,760)
COMPREHENSIVE INCOME (LOSS)	(20,535)	29,652	(3,822)	39,997
Net (income) loss attributable to redeemable noncontrolling interests	288	(3,574)	(3,099)	(2,980)
Other comprehensive (income) loss attributable to redeemable noncontrolling interests	1,503	(834)	2,886	(2,710)
Net loss attributable to noncontrolling interests	0	125	0	127
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO JBG SMITH PROPERTIES	$ (18,744)	$ 25,369	$ (4,035)	$ 34,434