Goodwill And Intangible Assets (Components Of Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Schedule of Indefinite-Lived And Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	$ 2,358,086	$ 2,196,597
Intangible assets, accumulated amortization	(619,612)	(470,401)
Customer Relationships [Member]
Schedule of Indefinite-Lived And Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	1,021,427	953,739
Intangible assets, accumulated amortization	(267,580)	(204,261)
Investment Management Agreements [Member]
Schedule of Indefinite-Lived And Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	468,000	441,000
Intangible assets, accumulated amortization	(33,345)	0
Broker Relationships [Member]
Schedule of Indefinite-Lived And Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	206,249	204,367
Intangible assets, accumulated amortization	(89,234)	(78,559)
Trade Names [Member]
Schedule of Indefinite-Lived And Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	208,959	193,154
Intangible assets, accumulated amortization	(68,961)	(62,827)
Technology [Member]
Schedule of Indefinite-Lived And Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	113,389	109,208
Intangible assets, accumulated amortization	(60,611)	(47,090)
Agent Relationships [Member]
Schedule of Indefinite-Lived And Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	92,000	92,000
Intangible assets, accumulated amortization	(16,355)	(10,175)
Insurance Licenses [Member]
Schedule of Indefinite-Lived And Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	74,635	74,635
Intangible assets, accumulated amortization	0	0
Renewal Rights [Domain]
Schedule of Indefinite-Lived And Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	21,449	21,053
Intangible assets, accumulated amortization	(19,366)	(18,272)
Other [Member]
Schedule of Indefinite-Lived And Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross carrying amount	151,978	107,441
Intangible assets, accumulated amortization	$ (64,160)	$ (49,217)