Leases (Tables)

12 Months Ended

Dec. 31, 2015

Leases [Abstract]

Future Minimum Lease Payments

The future minimum lease payments relating to operating leases are summarized as follows (in thousands of dollars):

2016	45,133
2017	37,585
2018	30,838
2019	22,517
2020	12,585
2021 and after	18,360
	167,018