Commitments and Contingencies (Details Textual 1) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended			6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012 Pittman Litigation [Member]	Jun. 30, 2012 Pittman Litigation [Member]	Jul. 20, 2012 Pittman Litigation [Member]	Apr. 29, 2011 Pittman Litigation [Member] Plaintiffs	Jun. 30, 2012 Pittman Litigation [Member] Goldman Sachs & Co. [Member]	Jun. 30, 2012 Pittman Litigation [Member] Other Parties [Member]
Loss Contingencies [Line Items]
Number of additional plaintiffs added to amended complaint								2
Settlement payment subject to preliminary and final approval to be distributed pro rata to certain stockholders							$ 10.0
Legal accruals and settlement charges	36.5	0.4	38.1	1.4	6.5	6.5
Contribution toward funding settlement						3.5
Contribution by director and officer liability policy						2.8
Contribution toward settlement payment in recognition of waiver of all future rights to receive cash or equity compensation						2.0
Contribution toward settlement payment in recognition of waiver of reimbursement of legal fees and expenses									$ 1.0	$ 0.8