Accumulated Other Comprehensive Income (Loss) (Summary of Changes in Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands		1 Months Ended	3 Months Ended		9 Months Ended
		Mar. 31, 2022	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022		Sep. 30, 2021
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period			$ 3,443,801	$ 3,671,903	$ 3,710,670		$ 3,715,023
Other comprehensive income (loss) before reclassifications			6,794	(201)	24,355		2,046
(Gain) loss reclassified from accumulated other comprehensive loss to net income			728	3,172	6,709		9,186
Share of investee's other comprehensive income	[1]		0	1,508	0		4,083
Reclassification of the Company's share of previously deferred derivative gains to net income	[2]		0	0	(6,723)		0
Net current-period other comprehensive income (loss)			7,522	4,479	24,341		15,315
Balance at the end of the period			3,550,891	3,682,584	3,550,891		3,682,584
Equity in earnings (losses) from real estate and other affiliates			7,708	(7,848)	19,528		15,815
AOCI, reclassification of cash flow hedge	[3]				6,723
Share of investee's other comprehensive income, tax expense (benefit)		$ 1,900		429	1,912	[3]	1,161
Disposal Group, Disposed of by Sale, Not Discontinued Operations | 110 North Wacker
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Equity in earnings (losses) from real estate and other affiliates		8,600
AOCI, reclassification of cash flow hedge		$ 6,700
AOCI Attributable to Parent
AOCI Attributable to Parent, Net of Tax [Roll Forward]
Balance at the beginning of the period			2,362	(27,754)	(14,457)		(38,590)
Share of investee's other comprehensive income				1,508			4,083
Balance at the end of the period			$ 9,884	$ (23,275)	9,884		$ (23,275)
AOCI, reclassification of cash flow hedge	[3]				$ 6,723

[1] Amount is shown net of tax expense of $0.4 million for the three months ended September 30, 2021, and $1.2 million for the nine months ended September 30, 2021.

[2] In March 2022, the Company completed the sale of its ownership interest in 110 North Wacker and released a net of $6.7 million from Accumulated other comprehensive income (loss), representing the Company’s $8.6 million share of previously deferred gains associated with the Venture’s derivative instruments net of tax expense of $1.9 million. See Note 2 - Investment in Real Estate and Other Affiliates for additional information.

[3] In March 2022, the Company completed the sale of its ownership interest in 110 North Wacker and released a net of $6.7 million from Accumulated other comprehensive income (loss), representing the Company’s $8.6 million share of previously deferred gains associated with the Venture’s derivative instruments net of tax expense of $1.9 million. See Note 2 - Investment in Real Estate and Other Affiliates for additional information.