Fair value measurement (Tables)

12 Months Ended

Dec. 31, 2017

Fair Value Disclosures [Abstract]

Financial Assets and Liabilities Carried at Fair Value Measured on Recurring Basis

The following tables provide information regarding the Company's financial assets and liabilities measured at fair value on a recurring basis as of December 31, 2017 and 2016:

	Basis of fair value measurement
	December 31, 2017		(Level 1)		(Level 2)		(Level 3)
	(Dollars in thousands)
Investments in marketable securities	$	9,045	$	9,045	$	—	$	—
Derivative assets	1,221		—		1,221		—
Derivative liabilities	1,426		—		1,426		—
Contingent consideration liabilities	272,136		—		—		272,136

	Basis of fair value measurement
	December 31, 2016		(Level 1)		(Level 2)		(Level 3)
	(Dollars in thousands)
Investments in marketable securities	$	7,660	$	7,660	$	—	$	—
Derivative assets	1,157		—		1,157		—
Derivative liabilities	2,257		—		2,257		—
Contingent consideration liabilities	7,102		—		—		7,102

Schedule of Valuation Techniques

The table below provides additional information regarding the valuation technique and inputs used in determining the fair value of contingent consideration recognized in connection with the NeoTract acquisition, which is described in Note 3.

	Valuation Technique	Unobservable Input	Range
Contingent consideration	Monte Carlo simulation	Revenue volatility	21.1	%
		Risk free rate	Cost of debt structure
		Projected year of payment	2018 - 2021

Reconciliation of Changes in Level 3 Financial Liabilities Measured at Fair Value on Recurring Basis

The following table provides information regarding changes in the Company's contingent consideration liabilities for the years ended December 31, 2017 and 2016:

	Contingent consideration
	2017			2016
	(Dollars in thousands)
Beginning balance – January 1	$	7,102		$	20,829
Initial estimate upon acquisition	261,733			—
Payments	(335		)	(7,282		)
Revaluations	3,575			(6,445		)
Translation adjustment	61			—
Ending balance – December 31	$	272,136		$	7,102