Goodwill and Intangible Assets (Details 1) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012	Dec. 31, 2011
Schedule of acquired intangible assets
Gross carrying amount	$ 57,108	$ 32,145
Accumulated amortization	22,573	19,590
Net	34,535	12,555
Client contracts and broker relationships [Member]
Schedule of acquired intangible assets
Gross carrying amount	44,424	26,534
Accumulated amortization	17,079	15,206
Net	27,345	11,328
Trade names [Member]
Schedule of acquired intangible assets
Gross carrying amount	2,010	1,020
Accumulated amortization	663	542
Net	1,347	478
Technology [Member]
Schedule of acquired intangible assets
Gross carrying amount	7,542	2,580
Accumulated amortization	3,104	2,177
Net	4,438	403
Noncompete agreements [Member]
Schedule of acquired intangible assets
Gross carrying amount	2,011	2,011
Accumulated amortization	1,685	1,665
Net	326	346
Favorable lease [Member]
Schedule of acquired intangible assets
Gross carrying amount	1,121
Accumulated amortization	42
Net	$ 1,079