Employee benefit plans - Schedule of Amounts Recognized in Accumulated Other Comprehensive Income (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Amounts recognized in the accumulated other comprehensive loss consist of:
Net amount recognized	$ 4,515	$ 5,111
Pension Benefits
Defined Benefit Plan Disclosure
Liabilities	4,059	5,049
Amounts recognized in the accumulated other comprehensive loss consist of:
Net actuarial gain	(6,946)	(7,863)
Deferred taxes	2,431	2,752
Net amount recognized	$ (4,515)	$ (5,111)

Defined Benefit Plan Accumulated Other Comprehensive Income Loss Deferred Tax

No definition available.

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- Definition

The total of net gain (loss), prior service cost (credit), and transition assets (obligations), as well as minimum pension liability if still remaining, included in accumulated other comprehensive income associated with a defined benefit pension or other postretirement plan(s) because they have yet to be recognized as components of net periodic benefit cost.

+ References

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-Publisher FASB
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- Definition

The pretax net amount of gains and losses that are not yet recognized as a component of net periodic benefit cost, and that are recognized as increases or decreases in other comprehensive income as they arise. Gains and losses are due to changes in the value of either the benefit obligation or the plan assets resulting from experience different from that assumed or from a change in an actuarial assumption, or the consequence of a decision to temporarily deviate from the substantive plan.

+ References

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- References

No definition available.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

This represents the noncurrent liability for underfunded plans recognized in the balance sheet that is associated with the defined benefit pension plans and other postretirement defined benefit plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
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