Revolving Line of Credit (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011
Revolving Line of Credit (Textual) [Abstract]
Line of credit facility, maximum borrowing capacity	$ 50,000,000		$ 50,000,000
Loan bears interest, description of variable rate basis			LIBOR plus 3%
Extend maturity period of revolving line of credit			1 year
Line of credit facility basis spread on variable rate	3.00%		3.00%
Line of credit facility, expiration date			Mar. 03, 2014
Line of credit facility extended maturity date			Mar. 03, 2015
Line of credit facility, amount outstanding	0		0		40,000,000
Line of credit facility, commitment fee amount	$ 44,000	$ 44,000	$ 106,000	$ 95,000