Subsequent Event (Details) (USD $) In Millions, except Per Share data	Sep. 30, 2011
Right to receive cash without interest subject to conditions set forth in the merger agreement for each outstanding share of common stock	$ 33.25
Obligated financial advisor fee in connection with merger	$ 22.5
Maximum [Member]
Obligated to pay termination fee if the merger agreement is terminated	116.2
Minimum [Member]
Obligated to pay termination fee if the merger agreement is terminated	$ 58.1