Summary of Significant Accounting Policies (Details) $ in Thousands, shares in Millions, ft² in Millions	3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2023 USD ($) ft² property financing_receivable state variable_interest_entity note_receivable shares	Mar. 31, 2023 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2023 USD ($) ft² property financing_receivable state variable_interest_entity joint_venture note_receivable shares	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Jun. 30, 2023 USD ($)	Jan. 01, 2023 USD ($) financing_receivable	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Business Overview:
Gross investment amount, total	$ 13,600,000			$ 13,600,000
Number of real estate properties | property	663			663
Number of owned real estate properties | property	663			663
Number of states that the company owns real estate in, whole units | state	35			35
Approximate square feet invested in by company | ft²	39.1			39.1
Approximate square feet for which Nationwide property management services provided by company | ft²	38.6			38.6
Number of buildings owned by joint venture with TIAA | property	34			34
Principles of Consolidation:
Equity ownership for consolidation (percent)	100.00%			100.00%
Number of variable interest entities | variable_interest_entity	4			4
Redeemable Non-Controlling Interests:
Redeemable non-controlling interests	$ 3,195		$ 0	$ 3,195	$ 0	$ 2,014	$ 2,487		$ 0	$ 0
Asset Impairment:
Impairment of real estate assets	56,900			138,300
Real Estate Notes Receivable:
Investment in financing receivable, net	$ 155,000			155,000
Allowance for Credit Losses, Interest Income, Income from Real Estate Notes Receivable:
Credit loss reserves		$ 5,200		$ 5,196		$ 0
Number of recognized lease financial receivables | financing_receivable	2			2
Income from financing receivables	$ 2,000		$ 2,000	$ 6,200	$ 5,900
Number of real estate notes receivable | financing_receivable								2
Financing receivable, nonaccrual								$ 48,900
Notes Receivable
Allowance for Credit Losses, Interest Income, Income from Real Estate Notes Receivable:
Interest income	$ 2,300			$ 6,500
Variable Interest Entity
Principles of Consolidation:
Number of variable interest entities | variable_interest_entity	3			3
Number of notes receivable | note_receivable	2			2
Number of joint ventures | joint_venture				1
Non-Controlling Interest Holders | Healthcare Trust of America Holdings L P
Principles of Consolidation:
Limited partner's capital, units outstanding (in shares) | shares	4.7			4.7
Limited partners ownership interest (in percent)				1.20%
Property Entities Not Determined to be VIEs
Principles of Consolidation:
Equity interest owned (percent)	100.00%			100.00%
Healthcare Trust of America Holdings L P
Principles of Consolidation:
Equity interest owned (percent)	98.80%			98.80%
Real Estate Properties Held in Joint Ventures
Business Overview:
Joint venture ownership (percent)	44.00%			44.00%