Intangible Assets (Details Textual) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Intangible Assets (Textual) [Abstract]
Amortization expense for intangible assets	$ 1,046,000	$ 1,232,000	$ 3,533,297	$ 3,549,062
Database [Member]
Intangible Assets (Textual) [Abstract]
Amount Capitalize Intangible Asset	520,000	512,000	1,459,000	1,427,000
Amortization expense for intangible assets	330,000	601,000	1,555,000	1,778,000
Customer relationships [Member]
Intangible Assets (Textual) [Abstract]
Amortization expense for intangible assets	246,000	247,000	738,000	744,000
Web site [Member]
Intangible Assets (Textual) [Abstract]
Amount Capitalize Intangible Asset	474,000	421,000	1,443,000	1,171,000
Amortization expense for intangible assets	396,000	308,000	1,013,000	800,000
Acquired below market lease [Member]
Intangible Assets (Textual) [Abstract]
Amortization expense for intangible assets	$ 75,000	$ 76,000	$ 227,000	$ 227,000