Commitments (Tables)

12 Months Ended

Dec. 31, 2017

Commitments And Contingencies Disclosure [Abstract]

Schedule of Future Minimum Lease Payments Under Operating Leases

Future minimum lease payments under operating leases as of December 31, 2017 are as follows:

(U.S. Dollars, in thousands)
2018	$	3,017
2019		2,018
2020		1,240
2021		1,575
2022		1,600
Thereafter		12,156
Total	$	21,606