Retirement Plans (Tables)

9 Months Ended

Sep. 30, 2018

Defined Benefit Plan Disclosure

Schedule of Costs of Retirement Plans

The following table summarizes the expense associated with the contributions made to these plans:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
United States	$	766	$	415	$	2,080	$	1,276
Canada	23		53		91		167
United Kingdom	114		93		328		306
	$	903	$	561	$	2,499	$	1,749

Pension Plan | United States

Defined Benefit Plan Disclosure

Schedule of Net Benefit Costs

Net periodic pension costs for the United States defined benefit pension plan for the three- and nine-month periods ended September 30, 2018 and 2017 were as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Interest cost	$	155	$	171	$	466	$	513
Expected return on plan assets	(213)		(178)		(640)		(533)
Recognized net actuarial loss	24		33		72		98
Net periodic pension (income) cost	$	(34)	$	26	$	(102)	$	78

Pension Plan | United Kingdom

Defined Benefit Plan Disclosure

Schedule of Net Benefit Costs

Net periodic pension costs for the United Kingdom defined benefit pension plan for the three- and nine-month periods ended September 30, 2018 and 2017 were as follows:

	Three Months Ended September 30,				Nine Months Ended September 30,
	2018		2017		2018		2017
Interest cost	$	51	$	56	$	153	$	168
Expected return on plan assets	(70)		(67)		(210)		(201)
Amortization of prior service costs and transition amount	5		4		15		12
Recognized net actuarial loss	48		72		144		216
Net periodic pension cost	$	34	$	65	$	102	$	195