Commitments and contingencies (Tables)

12 Months Ended

Dec. 31, 2016

Commitments and Contingencies Disclosure [Abstract]

Schedule of future rental payments under operating leases

Future rental payments under operating leases in respect of equipment rentals and leased premises are payable as follows:

Year ended December 31,	$’000
2017	12,028
2018	12,254
2019	10,549
2020	10,379
2021	10,935
2022 and thereafter	70,275
	126,420