Commitments, Contingencies and Concentrations of Risk (Tables)

12 Months Ended

Dec. 31, 2017

Commitments and Contingencies Disclosure [Abstract]

Schedule of minimum annual lease payments, excluding any renewals and extensions, property taxes, and other operating expenses, due under the agreements

The following schedule shows the minimum annual lease payments, excluding any renewals and extensions, property taxes, and other operating expenses, due under these agreements:

Year ending December 31,	Amount
	(dollars in thousands)
2018	$	7,170
2019	5,476
2020	2,675
2021	1,887
2022	1,421
Thereafter	2,312
Total	$	20,941