Share-Based Compensation and Benefit Plans (Other Share-Based Compensation Activity) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Employee stock purchase plan [Member]
Share-Based Compensation and Benefit Plans
Compensation expense for share-based compensation	$ 697	$ 632	$ 1,343	$ 1,209
Income tax benefit from compensation expense for share-based compensation	176	157	338	301
Restricted stock [Member]
Share-Based Compensation and Benefit Plans
Compensation expense for share-based compensation	351	348	702	687
Income tax benefit from compensation expense for share-based compensation	$ 88	$ 86	$ 177	$ 171