Business Combinations (Acquired Intangible Assets And Weighted-Average Useful Lives Of eCarlist Acquisition) (Details) (eCarList [Member], USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2011 years
Acquired Finite-Lived Intangible Assets [Line Items]
Total acquired identifiable intangible assets, Amount	$ 13,530
Weighted-average useful life of acquired identifiable intangible assets (years)	5.5
Customer Relationships [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Total acquired identifiable intangible assets, Amount	4,500
Weighted-average useful life of acquired identifiable intangible assets (years)	7.0
Technology [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Total acquired identifiable intangible assets, Amount	6,500
Weighted-average useful life of acquired identifiable intangible assets (years)	4.0
Non-Compete Agreements [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Total acquired identifiable intangible assets, Amount	730
Weighted-average useful life of acquired identifiable intangible assets (years)	5.0
Trade Names [Member]
Acquired Finite-Lived Intangible Assets [Line Items]
Total acquired identifiable intangible assets, Amount	$ 1,800
Weighted-average useful life of acquired identifiable intangible assets (years)	7.0