Commitments and Contingencies (Details) (USD $)	12 Months Ended
	Dec. 31, 2012
Anti-Trust Lawsuit [Abstract]
Amount of treble damages sought under the Sherman Antitrust Act and injunctive relief	$ 15,000,000
Contractual Commitment [Abstract]
Minimum remaining contractual cash obligations	49,500,000
Total minimum payments required under outsourcing agreement over remaining term	161,200,000
Estimate of remaining payments pursuant to outsourcing agreement	$ 331,300,000