Stock Incentive Plans (Details 3) (Restricted Stock [Member], USD $)	12 Months Ended
	Dec. 31, 2014
Restricted Stock [Member]
Non-vested stock incentive awards
Beginning Balance, Non-vested, shares	788,000
Beginning of Period, Non-vested , Weighted Average Grant Date Fair Value	$ 56.92
Vested, shares	(553,000)
Vested, Weighted Average Grant Date Fair Value	$ 56.29
Granted, shares	324,000
Granted, Weighted Average Grant Date Fair Value	$ 57.59
Terminated, shares	(5,000)
Terminated, Weighted Average Grant Date Fair Value	$ 57.2
Ending Balance, Non-vested, shares	554,000
Ending of Period, Non-vested, Weighted Average Grant Date Fair Value	$ 57.94