Retirement benefit plans (Tables)

12 Months Ended

Dec. 31, 2017

Retirement benefit plans

Obligations included in the balance sheet

	December 31,
	2017		2016		2015
	(Euro, in thousands)
Present value of funded defined benefit obligation	€	2,724	€	2,175
Plan assets		(2,555)		(1,789)	€	(1,064)
Deficit/ surplus		169		387		(1,064)
Present value of unfunded defined benefit obligation		3,412		3,133		2,693
Reclassification - Belgian contribution plans						1,064
Liability included in the balance sheet	€	3,582	€	3,520	€	2,693

Disclosure of present value of gross obligation

	2017		2016		2015
	(Euro, in thousands)
Opening balance	€	5,308	€	3,757	€	2,865
Current service cost		863		649		194
Actual taxes on contributions paid		(87)		(48)
Interest cost		87		82		50
Benefits paid		(157)		(119)		(44)
Reclassification - Belgian contribution plans						1,064
Actuarial gains (-) or losses due to experience adjustments		(100)		500		(27)
Actuarial gains (-) or losses due to experience adjustments related to new financial assumptions		222		432		(99)
Actuarial gains (-) or losses due to experience adjustments related to new demographic assumptions		—		56		(247)
Closing balance	€	6,136	€	5,308	€	3,757

Fair value of plan assets

	2017		2016		2015
	(Euro, in thousands)
Opening balance	€	(1,788)	€	(1,064)
Interest income on plan assets		(41)		(32)
Actual administration costs		3		2
Contributions from employer		(748)		(411)
Actual taxes on contributions paid		87		48
Plan assets gain during the period		(68)		(332)
Reclassification - Belgian contribution plans					€	(1,064)
Closing balance	€	(2,555)	€	(1,788)	€	(1,064)

Disclosure of amounts recognized in profit or loss

	Year ended December 31,
	2017		2016		2015
	(Euro, in thousands)
Current service cost	€	863	€	649	€	194
Interest cost		87		82		50
Interest income		(41)		(32)
Administration expenses		3		2
Revaluations of net liability / net asset		14		73		(171)
Total expense	€	926	€	773	€	73

Obligation reconciled in the balance sheet

	2017		2016		2015
	(Euro, in thousands)
Opening balance	€	3,520	€	2,693	€	2,865
Real employer contributions		(748)		(411)
Total expense recognized in the statement of operations		926		773		73
Re-measurement on the net defined benefit liability		40		583		(202)
Benefits paid		(157)		(119)		(44)
Closing balance	€	3,582	€	3,520	€	2,693

Disclosure of main actuarial assumptions

	December 31,
	2017		2016		2015
	%
Weighted average discount rate		1.48%		1.60%		2.00%
Expected salary increase		2.50%		2.50%		2.25%
Inflation rate		1.86%		1.75%		1.75%

Breakdown of defined benefit obligation

Breakdown of defined benefit obligation by type of plan participants:

	December 31,
	2017		2016		2015
		(number of participants)
Active plan participants		324		267		254

Breakdown of defined benefit obligation by type of benefits:

	December 31,
	2017		2016		2015
	(Euro, in thousands)
Retirement and death benefits	€	4,770	€	3,983	€	2,585
Other post-employment benefits		1,366		1,325		1,172

Major categories of plan assets

	December 31,
	2017		2016		2015
	(Euro, in thousands)
Equity	€	153	€	89	€	74
Debt		2,402		1,698		979
Cash		—		—		11

Sensitivity analysis on discount rate: effect on obligation

Sensitivity analysis on weighted average discount rate: effect on gross obligation:

		December 31,
		2017
		Obligation (Euro, in thousands)
Discount rate	0.98%	€	6,663
Discount rate	1.23%		6,393
Discount rate	1.48%		6,136
Discount rate	1.73%		5,895
Discount rate	1.98%	€	5,666

		December 31,
		2016
		Obligation (Euro, in thousands)
Discount rate	1.10%	€	3,792
Discount rate	1.35%		3,661
Discount rate	1.60%		3,520
Discount rate	1.85%		3,419
Discount rate	2.10%	€	3,312

			December 31,
			2015
			Obligation (Euro, in thousands)
Discount rate	1.50	%	€	2,868
Discount rate	1.75	%		2,779
Discount rate	2.00	%		2,693
Discount rate	2.25	%		2,612
Discount rate	2.50	%	€	2,534