Stock Options, Restricted Stock and Restricted Stock Units - Options (Details) - Stock options [Member] - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Schedule of stock option activity and other stock option information
Beginning Balance, Number of shares	100,000
Grants, Number of shares
Exercises, Number of shares		0
Forfeitures/Expirations, Number of shares
Ending Balance, Number of shares	100,000		100,000
Exercisable, Number of shares	100,000
Beginning Balance, Weighted-average exercise price	$ 51.95
Grants, Weighted-average exercise price
Exercises, Weighted-average exercise price
Forfeitures/Expirations, Weighted-average exercise price
Ending Balance, Weighted-average exercise price	51.95		$ 51.95
Exercisable, Weighted-average exercise price	$ 51.95
Weighted-average remaining contractual life (years)	2 years 9 months 18 days		3 years 1 month 6 days
Exercisable, Weighted-average remaining contractual life (years)	2 years 9 months 18 days
Beginning Balance, Aggregate intrinsic value	$ 3,763
Ending Balance, Aggregate intrinsic value	4,910		$ 3,763
Exercisable, Aggregate intrinsic value	$ 4,910