Summary of Significant Accounting Policies - Earnings per Share (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share Basic And Diluted [Line Items]
Net income attributable to Agree Realty Corporation	$ 18,564	$ 12,923	$ 36,911	$ 29,375
Less: Income attributable to unvested restricted shares	(89)	(88)	(185)	(201)
Net income used in basic and diluted earnings per share	$ 18,475	$ 12,835	$ 36,726	$ 29,174
Weighted average number of common shares outstanding	40,813,436	31,033,259	39,259,807	31,023,457
Less: Unvested restricted stock	(201,064)	(212,074)	(201,064)	(212,074)
Weighted average number of common shares outstanding used in basic earnings per share	40,612,372	30,821,185	39,058,743	30,811,383
Weighted average number of common shares outstanding used in basic earnings per share	40,612,372	30,821,185	39,058,743	30,811,383
Effect of dilutive securities: Share-based compensation	82,836	59,252	80,030	47,620
Effect of dilutive securities: forward equity offering	446,451		606,564
Weighted average number of common shares outstanding used in diluted earnings per share	41,141,659	31,222,221	39,745,337	31,036,694
March 2018 Forward Sale [Member]
Earnings Per Share Basic And Diluted [Line Items]
Effect of dilutive securities: forward equity offering		341,784		177,691
September 2018 Forward Sales
Earnings Per Share Basic And Diluted [Line Items]
Effect of dilutive securities: forward equity offering	312,464		539,570
April 2019 Forward Equity
Earnings Per Share Basic And Diluted [Line Items]
Effect of dilutive securities: forward equity offering	133,987	0	66,994	0

The amount net income (loss) attributable to unvested restricted stocks.

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