Share-Based Compensation - Information pertaining to options oustanding - (Details) - $ / shares	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Share Based Compensation
Range of exercise prices, low end of range (in dollars per share)	$ 61.42	$ 61.42
Range of exercise prices, high end of range (in dollars per share)	$ 69.48	$ 66.32
Restricted Stock
Vesting schedule of shares
Total	196,650		218,282