Share-Based Compensation and Benefit Plans (Stock Option) (Narrative) (Details) - Stock option [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Share-Based Compensation and Benefit Plans
Remaining unrecognized compensation expense	$ 31.3
Weighted-average period for cost recognition	2 years 7 months 15 days
Employee stock option [Member]
Share-Based Compensation and Benefit Plans
Vesting of options, description	The Company’s employee incentive plans provide for the granting of stock options for the purchase of common stock of the Company to certain key employees of the Company. Employee stock options are granted at an exercise price that is equal to the closing market price of the Company’s common stock on the date of the grant.
Options expiration date	10 years
Stock options outstanding	1,860,000	2,364,000
Options vesting period	4 years
Option vesting rate per year	25.00%
Director [Member]
Share-Based Compensation and Benefit Plans
Vesting of options, description	The Company’s director stock plan provides for the granting of stock options for the purchase of common stock of the Company to directors of the Company. Director stock options are granted at an exercise price that is equal to the closing market price of the Company’s common stock on the date of the grant.
Options expiration date	7 years
Stock options outstanding	0	0
Options vesting period	6 months