Basis of Presentation and Summary of Significant Accounting Policies (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Property and Equipment
Unamortized property and equipment	133,096	$ 108,814
Autos | Minimum
Property and Equipment
Estimated useful lives	3 years
Autos | Maximum
Property and Equipment
Estimated useful lives	5 years
Computers, software, machinery and equipment
Property and Equipment
Unamortized property and equipment	65,694	64,188
Computers, software, machinery and equipment | Minimum
Property and Equipment
Estimated useful lives	1 year
Computers, software, machinery and equipment | Maximum
Property and Equipment
Estimated useful lives	7 years
Leasehold improvements
Property and Equipment
Unamortized property and equipment	7,797	5,390
Leasehold improvements | Minimum
Property and Equipment
Estimated useful lives	1 year
Leasehold improvements | Maximum
Property and Equipment
Estimated useful lives	10 years
Furniture and fixtures
Property and Equipment
Unamortized property and equipment	6,020	4,900
Furniture and fixtures | Minimum
Property and Equipment
Estimated useful lives	3 years
Furniture and fixtures | Maximum
Property and Equipment
Estimated useful lives	15 years
Building and improvements
Property and Equipment
Unamortized property and equipment	18,674	10,401
Building and improvements | Minimum
Property and Equipment
Estimated useful lives	5 years
Building and improvements | Maximum
Property and Equipment
Estimated useful lives	31 years
Internally developed software
Property and Equipment
Unamortized property and equipment	14,400	$ 13,100