Summary of Significant Accounting Policies - Real Estate Properties (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Summary of Significant Accounting Policies
Land	$ 2,405	$ 2,269
Buildings	5,288	2,315
Lease Intangibles (Asset)	880
Real Estate Held-for-sale, Gross	8,573	4,584
Accumulated depreciation and amortization	(778)	(834)
Total Real Estate Held for Sale, net	$ 7,795	$ 3,750

- Definition

Gross amount as of investments in land, buildings and lease intangibles held for sale, excluding real estate considered to be inventory of the entity.

+ References

No definition available.

+ Details

Name:	adc_RealEstateHeldForSaleGross
Namespace Prefix:	adc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The amount of real estate investments, net of accumulated depreciation .

+ References

No definition available.

+ Details

Name:	adc_RealEstateHeldForSaleNetTotal
Namespace Prefix:	adc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The cumulative amount of depreciation for real estate property held for sale.

+ References

No definition available.

+ Details

Name:	adc_RealEstateHeldforsaleAccumulatedDepreciation
Namespace Prefix:	adc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Gross amount as of investments in buildings held for sale, excluding real estate considered to be inventory of the entity.

+ References

No definition available.

+ Details

Name:	adc_RealEstateHeldforsaleBuilding
Namespace Prefix:	adc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Gross amount as of investments in land held for sale, excluding real estate considered to be inventory of the entity.

+ References

No definition available.

+ Details

Name:	adc_RealEstateHeldforsaleLand
Namespace Prefix:	adc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Gross amount as of investments in lease intangibles held for sale, excluding real estate considered to be inventory of the entity.

+ References

No definition available.

+ Details

Name:	adc_RealEstateHeldforsaleLeaseIntangibles
Namespace Prefix:	adc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_AccountingPoliciesAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration