Stock Plans (Tables)

12 Months Ended

Dec. 31, 2017

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Share Based Compensation Activity

A summary of the status of the Company’s restricted stock units as of December 31, 2017 and changes during the year ended December 31, 2017, is presented below:

Restricted Stock Units	Shares			Weighted Average Grant-Date Fair Value
Nonvested shares at January 1, 2017		501,992		$	46.52
Granted		159,992			66.54
Vested		(237,262	)		42.98
Canceled		(10,958	)		57.15
Nonvested shares at December 31, 2017		413,764			54.57