Financial instruments (Tables)

3 Months Ended

Mar. 31, 2019

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 March 31, 2019 and December 31, 2018:

	March 31, 2019		December 31, 2018
	Fair Value
	(Dollars in thousands)
Asset derivatives:
Designated foreign currency forward contracts	$	883	$	1,216
Non-designated foreign currency forward contracts	264		106
Cross-currency interest rate swap	23,129		14,728
Prepaid expenses and other current assets	24,276		16,050
Cross-currency interest rate swap	11		—
Other assets	11		—
Total asset derivatives	24,287		16,050
Liability derivatives:
Designated foreign currency forward contracts	1,054		524
Non-designated foreign currency forward contracts	533		264
Other current liabilities	1,587		788
Cross-currency interest rate swap	3,713		7,793
Other liabilities	3,713		7,793
Total liability derivatives	$	5,300	$	8,581