Borrowing Arrangements - Fair Value of Mortgage Debt (Details) - Fair Value, Inputs, Level 2 - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value
Debt Instrument
Long-term Debt, Fair Value	$ 2,227,185	$ 2,164,563
Carrying Value
Debt Instrument
Long-term Debt, Fair Value	$ 2,072,416	$ 2,174,715

The fair value amount of long-term debt whether such amount is presented as a separate caption or as a parenthetical disclosure. Additionally, this element may be used in connection with the fair value disclosures required in the footnote disclosures to the financial statements. The element may be used in both the balance sheet and disclosure in the same submission.

No definition available.

Name:	us-gaap_LongTermDebtFairValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant