Notes Receivable, Net (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Feb. 17, 2012
Notes Receivable Net (Textual) [Abstract]
Principal amount of notes purchased					$ 30.0
Interest income recognized on notes receivable	$ 0	$ 0	$ 0.6	$ 0
Date acquired, notes receivable			Feb. 17, 2012
Notes receivable transferred with respect to the acquisition			Apr. 13, 2012