Share-Based Compensation (Summary of Grant Date Fair Value of Awards) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Grant date fair value of awards during the period:
Options	$ 127	$ 53	$ 20,071	$ 12,580
Restricted stock	876	1,247	4,584	3,361
Total	1,003	1,300	24,655	15,941
Share-based compensation expense:
Options	2,057	1,368	3,282	2,126
Restricted stock	986	607	1,791	1,573
Total	3,043	1,975	5,073	3,699
Income tax benefit/(deficiency) related to share-based compensation [Abstract]
Options	488	300	731	601
Restricted stock	304	57	455	219
Total	$ 792	$ 357	$ 1,186	$ 820