Stock Incentive Plans (Details 3) - Restricted Stock [Member]	12 Months Ended
	Dec. 31, 2015 $ / shares shares
Non-vested stock incentive awards
Beginning Balance, Non-vested, shares | shares	554,000
Beginning of Period, Non-vested , Weighted Average Grant Date Fair Value | $ / shares	$ 56.92
Vested, shares | shares	(306,000)
Vested, Weighted Average Grant Date Fair Value | $ / shares	$ 61.09
Granted, shares | shares	449,000
Granted, Weighted Average Grant Date Fair Value | $ / shares	$ 66.93
Terminated, shares | shares	(59,000)
Terminated, Weighted Average Grant Date Fair Value | $ / shares	$ 66.09
Ending Balance, Non-vested, shares | shares	638,000
Ending of Period, Non-vested, Weighted Average Grant Date Fair Value | $ / shares	$ 62