Fair Value Measurements - Liabilities (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Total Fair Value Inputs [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Large Capitalization Registered Investment Companies	$ 388	$ 405
Mid Capitalization Registered Investment Companies	106	109
Small Capitalization Registered Investment Companies	89	95
International Developed And Emerging Markets Registered Investment Companies	198	205
Fixed Income Registered Investment Companies	41	43
Fixed General Account	156	167
Acquisition-related Consideration	62	4,876
Liabilities, Fair Value Disclosure	1,040	5,900
Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Large Capitalization Registered Investment Companies	388	405
Mid Capitalization Registered Investment Companies	106	109
Small Capitalization Registered Investment Companies	89	95
International Developed And Emerging Markets Registered Investment Companies	198	205
Fixed Income Registered Investment Companies	41	43
Fixed General Account	0	0
Acquisition-related Consideration	0	0
Liabilities, Fair Value Disclosure	822	857
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Large Capitalization Registered Investment Companies	0	0
Mid Capitalization Registered Investment Companies	0	0
Small Capitalization Registered Investment Companies	0	0
International Developed And Emerging Markets Registered Investment Companies	0	0
Fixed Income Registered Investment Companies	0	0
Fixed General Account	156	167
Acquisition-related Consideration	0	0
Liabilities, Fair Value Disclosure	156	167
Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Large Capitalization Registered Investment Companies	0	0
Mid Capitalization Registered Investment Companies	0	0
Small Capitalization Registered Investment Companies	0	0
International Developed And Emerging Markets Registered Investment Companies	0	0
Fixed Income Registered Investment Companies	0	0
Fixed General Account	0	0
Acquisition-related Consideration	62	4,876
Liabilities, Fair Value Disclosure	$ 62	$ 4,876