Equity Compensation, Employment Agreements and Other Benefit Plans (Expense Allocation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense related to equity-based compensation instruments	$ 8,033	$ 9,162	$ 7,832
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense related to equity-based compensation instruments	1,935	4,326	4,373
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense related to equity-based compensation instruments	6,098	4,792	3,377
DER
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense related to equity-based compensation instruments	0	$ 44	$ 82
Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expense related to equity-based compensation instruments	$ 900