Property and Equipment (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Summary of property and equipment
Property and equipment, at cost	$ 183,746	$ 171,452
Accumulated depreciation	(111,108)	(102,124)
Property and equipment, net	72,638	69,328
Depreciation	12,834	13,211	14,764
Leasehold improvements
Summary of property and equipment
Property and equipment, at cost	19,991	19,610
Leasehold improvements | Minimum
Summary of property and equipment
Estimated useful lives	1 year
Leasehold improvements | Maximum
Summary of property and equipment
Estimated useful lives	15 years
Furniture and fixtures
Summary of property and equipment
Property and equipment, at cost	32,688	30,670
Furniture and fixtures | Minimum
Summary of property and equipment
Estimated useful lives	3 years
Furniture and fixtures | Maximum
Summary of property and equipment
Estimated useful lives	10 years
Equipment
Summary of property and equipment
Property and equipment, at cost	19,984	19,660
Equipment | Minimum
Summary of property and equipment
Estimated useful lives	3 years
Equipment | Maximum
Summary of property and equipment
Estimated useful lives	26 years
Computer software
Summary of property and equipment
Property and equipment, at cost	80,692	74,081
Computer software | Minimum
Summary of property and equipment
Estimated useful lives	1 year
Computer software | Maximum
Summary of property and equipment
Estimated useful lives	10 years
Data processing equipment
Summary of property and equipment
Property and equipment, at cost	22,374	20,207
Data processing equipment | Minimum
Summary of property and equipment
Estimated useful lives	2 years
Data processing equipment | Maximum
Summary of property and equipment
Estimated useful lives	5 years
Property and equipment under capital leases
Summary of property and equipment
Property and equipment, at cost	1,900	1,900
Accumulated depreciation	900	800
Buildings
Summary of property and equipment
Property and equipment, at cost	6,077	5,284
Buildings | Minimum
Summary of property and equipment
Estimated useful lives	5 years
Buildings | Maximum
Summary of property and equipment
Estimated useful lives	30 years
Land
Summary of property and equipment
Property and equipment, at cost	$ 1,940	$ 1,940