Consolidated and Combined Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement of Comprehensive Income [Abstract]
NET INCOME (LOSS)	$ 74,144	$ 46,613	$ (79,084)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax	(27,722)	5,382	1,438
Other Comprehensive Income (Loss) [Abstract]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax	(1,694)	(1,090)	(399)
Other comprehensive income (loss)	26,028	(6,472)	(1,837)
COMPREHENSIVE INCOME (LOSS)	48,116	53,085	(77,247)
Net (income) loss attributable to redeemable noncontrolling interests	(8,573)	(6,710)	7,328
Other comprehensive (income) loss attributable to redeemable noncontrolling interests	2,584	(1,384)	(225)
Net loss attributable to noncontrolling interests	0	21	3
COMPREHENSIVE INCOME (LOSS) ATTRIBUTABLE TO JBG SMITH PROPERTIES	$ 42,127	$ 45,012	$ (70,141)