Goodwill and Other Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Other Intangible Assets [Abstract]
Gross carrying amount	$ 93,872		$ 93,872
Accumulated amortization	58,928		58,928
Estimated aggregate amortization expense [Abstract]
For the remaining three months of the year ending December 31: 2014	3,239		3,239
For the year ending December 31: 2015	9,896		9,896
For the year ending December 31: 2016	8,484		8,484
For the year ending December 31: 2017	6,335		6,335
For the year ending December 31: 2018	4,107		4,107
Thereafter	2,883		2,883
Total	34,944		34,944
Amortization included in cost of sales and operating expenses [Abstract]
Total amortization	3,961	3,550	10,622	10,715
Amortization included in cost of sales [Member]
Amortization included in cost of sales and operating expenses [Abstract]
Total amortization	1,465	1,425	4,224	4,474
Amortization included in operating expenses [Member]
Amortization included in cost of sales and operating expenses [Abstract]
Total amortization	2,496	2,125	6,398	6,241
Purchased Software [Member]
Other Intangible Assets [Abstract]
Weighted average remaining amortization period (years)			2 years 9 months 18 days
Gross carrying amount	32,497		32,497
Accumulated amortization	20,327		20,327
Amortization included in cost of sales and operating expenses [Abstract]
Increase in intangible assets during the period			300
Write-off of fully amortized intangible assets			390
Purchased Software [Member] | Amortization included in cost of sales [Member]
Amortization included in cost of sales and operating expenses [Abstract]
Total amortization	1,316	1,131	3,832	3,388
Capitalized Software [Member]
Other Intangible Assets [Abstract]
Weighted average remaining amortization period (years)			4 years 9 months 18 days
Gross carrying amount	5,049		5,049
Accumulated amortization	1,903		1,903
Amortization included in cost of sales and operating expenses [Abstract]
Increase in intangible assets during the period			3,139
Capitalized Software [Member] | Amortization included in cost of sales [Member]
Amortization included in cost of sales and operating expenses [Abstract]
Total amortization	91	38	218	113
Customer Relationships [Member]
Other Intangible Assets [Abstract]
Weighted average remaining amortization period (years)			4 years 9 months 18 days
Gross carrying amount	43,664		43,664
Accumulated amortization	25,976		25,976
Amortization included in cost of sales and operating expenses [Abstract]
Depreciation and amortization	727
Write-off of fully amortized intangible assets	2,520		2,670
Customer Relationships [Member] | Amortization included in operating expenses [Member]
Amortization included in cost of sales and operating expenses [Abstract]
Total amortization	2,345	1,971	5,905	5,777
Backlog [Member]
Other Intangible Assets [Abstract]
Weighted average remaining amortization period (years)			0 years 3 months 18 days
Gross carrying amount	8,100		8,100
Accumulated amortization	8,042		8,042
Amortization included in cost of sales and operating expenses [Abstract]
Write-off of fully amortized intangible assets	1,580		1,580
Backlog [Member] | Amortization included in cost of sales [Member]
Amortization included in cost of sales and operating expenses [Abstract]
Total amortization	58	256	174	973
Trade Names [Member]
Other Intangible Assets [Abstract]
Weighted average remaining amortization period (years)			6 years 4 months 24 days
Gross carrying amount	1,463		1,463
Accumulated amortization	724		724
Trade Names [Member] | Amortization included in operating expenses [Member]
Amortization included in cost of sales and operating expenses [Abstract]
Total amortization	40	39	120	119
Non-competes [Member]
Other Intangible Assets [Abstract]
Weighted average remaining amortization period (years)			2 years 7 months 6 days
Gross carrying amount	3,099		3,099
Accumulated amortization	1,956		1,956
Amortization included in cost of sales and operating expenses [Abstract]
Write-off of fully amortized intangible assets			90
Non-competes [Member] | Amortization included in operating expenses [Member]
Amortization included in cost of sales and operating expenses [Abstract]
Total amortization	$ 111	$ 115	$ 373	$ 345