Goodwill And Intangible Assets (Schedule Of Acquired Intangible Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	$ 141,818	$ 78,024
Accumulated amortization	47,042	35,238
Net	94,776	42,786
Client Contracts And Broker Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	120,723	62,689
Accumulated amortization	33,885	25,313
Net	86,838	37,376
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	3,880	2,240
Accumulated amortization	1,657	1,120
Net	2,223	1,120
Technology [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	13,846	9,946
Accumulated amortization	9,390	6,850
Net	4,456	3,096
Noncompete Agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	2,232	2,012
Accumulated amortization	1,798	1,745
Net	434	267
Favorable Lease [Member]
Finite-Lived Intangible Assets [Line Items]
Gross carrying amount	1,137	1,137
Accumulated amortization	312	210
Net	$ 825	$ 927