Other non-current liabilities (Tables)

6 Months Ended

Jun. 30, 2018

Liabilities, Noncurrent [Abstract]

Summary of Other Non-Current Liabilities

Other non-current liabilities consist of the following:

	As of
	June 30, 2018		December 31, 2017
Derivative instruments	$	5,788	$	322
Unrecognized tax benefits	892		892
Deferred rent	7,632		8,176
Retirement benefits	3,363		3,377
Other non-current liabilities	1,155		3,435
Non-current liabilities	$	18,830	$	16,202