Goodwill And Intangible Assets (Schedule Of Acquired Intangible Assets) (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 259,322	$ 259,113
Accumulated amortization	(129,227)	(103,744)
Net	130,095	155,369
Client Contracts And Broker Relationships
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	237,430	237,221
Accumulated amortization	(108,834)	(84,581)
Net	128,596	152,640
Trade Names
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	3,880	3,880
Accumulated amortization	(3,587)	(3,492)
Net	293	388
Technology
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	14,646	14,646
Accumulated amortization	(14,009)	(13,047)
Net	637	1,599
Noncompete Agreements
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,232	2,232
Accumulated amortization	(2,084)	(2,013)
Net	148	219
Favorable Lease
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,134	1,134
Accumulated amortization	(713)	(611)
Net	$ 421	$ 523