Financial instruments (Tables)

6 Months Ended

Jul. 01, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Fair Values of Derivative Instruments Designated as Hedging Instruments

The following table presents the locations in the condensed consolidated balance sheet and fair value of derivative financial instruments as of July 1, 2018 and December 31, 2017:



	July 1, 2018		December 31, 2017
	Fair Value
	(Dollars in thousands)
Asset derivatives:
Designated foreign currency forward contracts	$	1,513	$	914
Non-designated foreign currency forward contracts	441		307
Prepaid expenses and other current assets	$	1,954	$	1,221
Total asset derivatives	$	1,954	$	1,221
Liability derivatives:
Designated foreign currency forward contracts	$	759	$	1,373
Non-designated foreign currency forward contracts	102		53
Other current liabilities	$	861	$	1,426
Total liability derivatives	$	861	$	1,426

Aggregate Accounts Receivable, Net of Allowance for Doubtful Accounts

The following table provides information regarding the Company's allowance for doubtful accounts, the aggregate net current and long-term trade accounts receivable related to customers in Greece, Italy, Spain and Portugal and the percentage of the Company’s total net current and long-term trade accounts receivable represented by these customers' trade accounts receivable at July 1, 2018 and December 31, 2017:



	July 1, 2018			December 31, 2017
	(Dollars in thousands)
Allowance for doubtful accounts ₍₁₎	$	9,525		$	10,255
Current and long-term trade accounts receivable, net in Greece, Italy, Spain and Portugal ₍₂₎	$	52,569		$	49,054
Percentage of total net current and long-term trade accounts receivable - Greece, Italy, Spain and Portugal	15.0		%	14.6		%

(1) The current portion of the allowance for doubtful accounts was $3.6 million and $3.5 million as of July 1, 2018 and December 31, 2017, respectively, and was recognized in accounts receivable, net.


(2)	The long-term portion of trade accounts receivable, net from customers in Greece, Italy, Spain and Portugal at July 1, 2018 and December 31, 2017 was $3.5 million and $3.3 million, respectively.