Intangible assets Future amortization expense (Tables)

12 Months Ended

Dec. 31, 2017

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
2018	$	875
2019	1,111
2020	1,254
2021	1,363
2022	1,154
Thereafter	6,056
	$	11,813