Summary of Significant Accounting Policies (Details) $ in Thousands, shares in Millions, ft² in Millions	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2023 USD ($) ft² financing_receivable variable_interest_entity property note_receivable state shares	Jun. 30, 2022 USD ($)	Jun. 30, 2023 USD ($) ft² financing_receivable property variable_interest_entity note_receivable state joint_venture shares	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Mar. 31, 2023 USD ($)	Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Business Overview:
Gross investment amount, total	$ 13,900,000		$ 13,900,000
Number of real estate properties | property	680		680
Number of owned real estate properties | property	680		680
Number of states that the company owns real estate in, whole units | state	35		35
Approximate square feet invested in by company | ft²	39.8		39.8
Approximate square feet for which Nationwide property management services provided by company | ft²	39.3		39.3
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	$ 2,487	$ 0	$ 2,487	$ 0	$ 2,014	$ 2,000	$ 0	$ 0
Asset Impairment:
Impairment of real estate assets	55,200		81,400
Real Estate Notes Receivable:
Investment in financing receivable, net	$ 151,500		151,500
Allowance for Credit Losses, Interest Income, Income from Real Estate Notes Receivable:
Credit loss reserves			$ 5,196		$ 0
Number of recognized lease financial receivables | financing_receivable	2		2
Income from financing receivables	$ 2,100	$ 2,000	$ 4,200	$ 3,900
Number of real estate notes receivable | financing_receivable	2		2
Financing receivable, nonaccrual	$ 48,900		$ 48,900
Notes Receivable
Allowance for Credit Losses, Interest Income, Income from Real Estate Notes Receivable:
Interest income	$ 2,200		$ 4,300
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 Trustof 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 Trustof 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%