Intangible assets Future amortization expense (Tables)

12 Months Ended

Dec. 31, 2018

Future intangible asset amortization expense [Abstract]

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

The estimated aggregate amortization expense for each of the next five years are as follows:

	(Dollars in thousands)
Year	Amortization
2020	$	1,495
2021	1,611
2022	1,406
2023	1,292
2024	1,196
Thereafter	5,335
	$	12,335