Description of Business and Summary of Significant Accounting Policies (Finite-lived Intangible Assets) (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible assets, gross	$ 80,607,000		$ 80,607,000		$ 75,191,000
Finite-lived intangible assets, accumulated amortization	(27,939,000)		(27,939,000)		(22,600,000)
Finite-lived intangible assets, net	52,668,000		52,668,000		52,591,000
Amortization of Acquired Intangible Assets	1,900,000	1,400,000	5,400,000	4,300,000
Customer Relationships [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible assets, gross	62,445,000		62,445,000		57,638,000
Customer Relationships [Member] | Minimum [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible asset, useful life			7 years
Customer Relationships [Member] | Maximum [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible asset, useful life			20 years
Developed technology [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible assets, gross	14,635,000		14,635,000		14,025,000
Developed technology [Member] | Minimum [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible asset, useful life			3 years
Developed technology [Member] | Maximum [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible asset, useful life			12 years
Trademarks [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible assets, gross	2,637,000		2,637,000		2,638,000
Trademarks [Member] | Minimum [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible asset, useful life			3 years
Trademarks [Member] | Maximum [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible asset, useful life			15 years
Non-compete agreements [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible assets, gross	538,000		538,000		538,000
Non-compete agreements [Member] | Maximum [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible asset, useful life			5 years
Backlog [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible assets, gross	140,000		140,000		140,000
Database [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible assets, gross	212,000		212,000		212,000
Database [Member] | Maximum [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Finite-lived intangible asset, useful life			10 years
Customer/territorial relationships [Member]
Finite-Lived and Indefinite-Lived Intangible Assets [Line items]
Indefinite-lived intangible assets	$ 30,887,000		$ 30,887,000		$ 30,887,000