Shareholders' Equity/Partners' Capital (AOCI by Component) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance, value	$ 6,753,185	$ 7,293,212	$ 6,948,155	$ 7,310,978
Ending balance, value	6,568,317	6,928,909	6,568,317	6,928,909
Total
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance, value	(60,753)	(82,719)	(75,099)	(40,233)
Other comprehensive income (loss)	9,316	73	23,662	(42,413)
Ending balance, value	(51,437)	(82,646)	(51,437)	(82,646)
Accumulated other comprehensive (loss) income of nonconsolidated subsidiaries
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance, value	(10,747)	12	(14,338)	4
Other comprehensive income (loss)	1,468	0	5,059	8
Ending balance, value	(9,279)	12	(9,279)	12
Interest rate swaps
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance, value	(54,456)	(81,603)	(66,098)	(36,126)
Other comprehensive income (loss)	8,551	78	20,193	(45,399)
Ending balance, value	(45,905)	(81,525)	(45,905)	(81,525)
Other
AOCI Including Portion Attributable to Noncontrolling Interest, Net of Tax [Roll Forward]
Beginning balance, value	4,450	(1,128)	5,337	(4,111)
Other comprehensive income (loss)	(703)	(5)	(1,590)	2,978
Ending balance, value	$ 3,747	$ (1,133)	$ 3,747	$ (1,133)