Related Party Transactions (Details) (USD $)	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Related Party Transactions [Abstract]
Revenue from client facilities in which the Related Parties have ownership interests		$ 4,145,000	$ 5,268,000
Fees paid to related party firm, maximum	100,000	100,000	100,000
Percentage of fee paid to related party in relation to related party's total revenue, maximum	5.00%	5.00%	5.00%
Accounts receivable		$ 750,000