Stock Repurchase Plan (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012
Accelerated Stock Buyback (Details) [Abstract]
Accelerated stock buyback, gross price paid	$ 200,000,000
Accelerated stock buyback, initial shares delivered, shares	4,592,423
Accelerated stock buyback, additional shares delivered at settlement, shares	816,916
Accelerated stock buyback, total shares delivered, shares	5,409,339
Stock Repurchase Plan (Details) [Abstract]
Authorized aggregate amount	1,250,000,000
Total number of shares repurchased since inception of our stock repurchase program (shares)	36,994,653	31,120,279
Aggregate purchase price of shares repurchased since inception of our stock repurchase program	994,800,000	777,300,000
Number of shares repurchased (shares)	465,035
Purchase price of shares repurchased	$ 17,400,000