Share-Based Payments (Details 2)	12 Months Ended
	Dec. 31, 2016 $ / shares shares
Stock Option Activity
Beginning Balance, Outstanding shares | shares	107,000
Beginning Balance, Weighted Average Exercise Price | $ / shares	$ 53.94
Shares, Granted | shares	0
Weighted Average Exercise Price, Granted | $ / shares	$ 0.00
Shares, Exercised | shares	(41,000)
Weighted Average Exercise Price, Exercised | $ / shares	$ 53.75
Shares, Cancelled | shares	0
Weighted Average Exercise Price, Cancelled | $ / shares	$ 0.00
Ending Balance, Outstanding shares | shares	66,000
Ending Balance, Weighted Average Exercise Price | $ / shares	$ 54.06