The cash outflow to repay long-term debt that is not secured by collateral. Excludes repayments of tax exempt unsecured debt.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121586364&loc=d3e3291-108585

Name:	us-gaap_RepaymentsOfUnsecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Notes Payable and Unsecured Credit Facilities Schedule of maturities of long-term debt (Parenthetical) (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Repayments of unsecured debt		$ 300,000	$ 250,000	$ 150,000
Subsequent Event [Member] \| Unsecured Debt [Member] \| Term Loan [Member]
Debt Instrument [Line Items]
Repayments of unsecured debt	$ 265,000