Treasury Stock (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended	9 Months Ended		26 Months Ended
	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013
Equity, Class of Treasury Stock [Line Items]
Treasury Stock, Value, Acquired, Cost Method		$ 234,000	$ 546,000
Stock Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Stock Repurchase Program, Authorized Amount				300,000,000
Treasury stock, shares, acquired (in shares)	8.4	0	16.5	45.0
Treasury Stock, Value, Acquired, Cost Method	41,800,000		79,500,000	208,400,000
Share Repurchase Program Commission Incurred	200,000		300,000	900,000
Treasury Stock Acquired, Average Cost Per Share	$ 4.99		$ 4.83
Accrued Liability for Repurchased but Unpaid Treasury Stock		0		0
Stock Repurchase Program, Remaining Authorized Repurchase Amount		$ 91,600,000