Stock Based Compensation (Tables)

3 Months Ended

Mar. 31, 2019

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

Schedule of Share-based Compensation, Restricted Stock and Restricted Stock Units Activity [Table Text Block]

During the three months ended March 31, 2019, the Company made the following awards of restricted stock:

Date	Shares Granted	Plan	Grant Date Fair Value Per Share		Vesting Period
2/21/2019	43,250	2005 Employee Stock Plan	$	83.87	Ratably over 5 years from grant date
3/15/2019	600	2005 Employee Stock Plan	$	79.55	Ratably over 5 years from grant date

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

The Company did not grant any awards of options to purchase shares of common stock during the three months ended March 31, 2019.