Consolidated Statements Of Shareholders' Equity (Unaudited) - USD ($) $ in Thousands		Total		Preferred Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Retained Earnings [Member] Cumulative Adjustments for Accounting Changes [Member] Revision of Prior Period, Adjustment	AOCI Attributable to Parent	Treasury Stock	Noncontrolling Interest	Parent [Member]
Balance, beginning of period at Dec. 31, 2019				$ 310,000	$ 16,749	$ 1,903,703	$ 1,715,704	$ (7,772)	$ (11,705)	$ (319,660)	$ 54,999
Common stock repurchased		$ (56,500)								(56,517)
Unit amortization, net of forfeitures						60,616
Distributions under employee plans						(109,986)	(47,511)			58,567
Net income		194,476					194,476
Dividends declared, Common							(28,938)
Dividends declared, Preferred							(9,687)
Issuance of preferred stock				225,000		(7,020)
Dividends declared to equity-award holders						350
Unrealized gains on securities, net of tax	[1]	3,344
Unrealized gains on cash flow hedging activities, net of tax									2,317
Foreign currency translation adjustment, net of tax		(9,978)							(9,978)
Other						(55)	2,063
Deconsolidation of non-controlling interest											$ (54,999)
Balance, end of period at Jun. 30, 2020		3,884,060		535,000	16,749	1,847,608	1,818,335		(16,022)	(317,610)		$ 3,884,060
Balance, beginning of period at Mar. 31, 2020				310,000	16,749	1,832,367	1,728,911		(96,460)	(321,241)
Common stock repurchased										(357)
Unit amortization, net of forfeitures						26,817
Distributions under employee plans						(4,416)	(794)			3,988
Net income		107,887					107,887
Dividends declared, Common							(14,022)
Dividends declared, Preferred							(4,843)
Issuance of preferred stock				225,000		(7,020)
Unrealized gains on securities, net of tax		76,571	[1]						76,571
Unrealized gains on cash flow hedging activities, net of tax									4,023
Foreign currency translation adjustment, net of tax		(156)							(156)
Other						(140)	1,196
Balance, end of period at Jun. 30, 2020		3,884,060		535,000	16,749	1,847,608	1,818,335		(16,022)	(317,610)		3,884,060
Balance, beginning of period at Dec. 31, 2020		4,238,766		535,000	16,749	1,888,982	2,078,135		27,639	(307,739)
Common stock repurchased		(41,700)								(41,007)
Unit amortization, net of forfeitures						64,245
Distributions under employee plans						(106,297)	(29,146)			65,628
Net income		371,092					371,092
Dividends declared, Common							(37,304)
Dividends declared, Preferred							(16,578)
Unrealized gains on securities, net of tax	[1]	(5,118)
Foreign currency translation adjustment, net of tax		4,745							4,745
Other						56	(292)
Balance, end of period at Jun. 30, 2021		4,508,790		535,000	16,749	1,846,986	2,365,907		27,266	(283,118)		4,508,790
Balance, beginning of period at Mar. 31, 2021				535,000	16,749	1,814,616	2,202,701		7,305	(257,499)
Common stock repurchased		(29,000)								(28,969)
Unit amortization, net of forfeitures						29,434
Distributions under employee plans						2,927	(7,559)			3,350
Net income		198,077					198,077
Dividends declared, Common							(18,834)
Dividends declared, Preferred							(8,289)
Unrealized gains on securities, net of tax		17,552	[1]						17,552
Foreign currency translation adjustment, net of tax		2,409							2,409
Other						9	(189)
Balance, end of period at Jun. 30, 2021		$ 4,508,790		$ 535,000	$ 16,749	$ 1,846,986	$ 2,365,907		$ 27,266	$ (283,118)		$ 4,508,790

[1] There were no reclassifications to earnings for the three and six months ended June 30, 2021. Reclassifications to earnings were immaterial for the three and six months ended June 30, 2020.