Stock Based Compensation (Tables)

9 Months Ended

Sep. 30, 2020

Share-based Payment Arrangement [Abstract]

Share-based Payment Arrangement, Restricted Stock and Restricted Stock Unit, Activity [Table Text Block]

During the nine months ended September 30, 2020, the Company made the following awards of time vested restricted stock:

Date	Shares Granted	Plan	Grant Date Fair Value Per Share		Vesting Period
2/27/2020	46,550	2005 Employee Stock Plan	$	70.24	Ratably over 5 years from grant date
4/15/2020	880	2005 Employee Stock Plan	$	68.14	Ratably over 5 years from grant date
5/27/2020	9,438	2018 Non-Employee Director Stock Plan	$	72.86	Shares vested immediately

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 nine months ended September 30, 2020.