Pension and Non-pension Postretirement Benefits

We have pension plans covering the majority of our employees. Benefits generally are based on compensation and service for salaried employees and job grade and length of service for hourly employees. In addition, we have an unfunded supplemental employee retirement plan (SERP) that covers certain salaried U.S.-based employees of Libbey hired before January 1, 2006. The U.S. pension plans cover the salaried U.S.-based employees of Libbey hired before January 1, 2006 and most hourly U.S.-based employees (excluding employees hired at Shreveport after December 15, 2008 and at Toledo after September 30, 2010). Effective January 1, 2013, we ceased annual company contribution credits to the cash balance accounts in our Libbey U.S. Salaried Pension Plan and SERP. The non-U.S. pension plans cover the employees of our wholly owned subsidiary in Mexico and are unfunded.

The components of our net pension expense, including the SERP, are as follows:



Three months ended June 30,	U.S. Plans						Non-U.S. Plans						Total
(dollars in thousands)	2017			2016			2017			2016			2017			2016
Service cost	$	883		$	863		$	277		$	318		$	1,160		$	1,181
Interest cost	3,442			3,705			701			670			4,143			4,375
Expected return on plan assets	(5,623		)	(5,760		)	—			—			(5,623		)	(5,760		)
Amortization of unrecognized:
Prior service cost (credit)	59			66			(52		)	(53		)	7			13
Actuarial loss	1,265			1,016			152			203			1,417			1,219
Settlement charge	—			42			—			170			—			212
Pension expense	$	26		$	(68	)	$	1,078		$	1,308		$	1,104		$	1,240

Six months ended June 30,	U.S. Plans						Non-U.S. Plans						Total
(dollars in thousands)	2017			2016			2017			2016			2017			2016
Service cost	$	1,958		$	1,859		$	528		$	635		$	2,486		$	2,494
Interest cost	6,892			7,482			1,338			1,342			8,230			8,824
Expected return on plan assets	(11,240		)	(11,515		)	—			—			(11,240		)	(11,515		)
Amortization of unrecognized:
Prior service cost (credit)	118			132			(99		)	(107		)	19			25
Actuarial loss	2,617			2,136			290			405			2,907			2,541
Settlement charge	—			42			—			170			—			212
Pension expense	$	345		$	136		$	2,057		$	2,445		$	2,402		$	2,581

We have contributed $0.6 million and $1.9 million of cash into our pension plans for the three months and six months ended June 30, 2017, respectively. Pension contributions for the remainder of 2017 are estimated to be $0.6 million.

We provide certain retiree health care and life insurance benefits covering our U.S. and Canadian salaried employees hired before January 1, 2004 and a majority of our union hourly employees (excluding employees hired at Shreveport after December 15, 2008 and at Toledo after September 30, 2010). Employees are generally eligible for benefits upon retirement and completion of a specified number of years of creditable service. Benefits for most hourly retirees are determined by collective bargaining. The U.S. non-pension postretirement plans cover the hourly and salaried U.S.-based employees of Libbey (excluding those mentioned above). The non-U.S. non-pension postretirement plans cover the retirees and active employees of Libbey who are located in Canada. The postretirement benefit plans are unfunded.

The provision for our non-pension postretirement benefit expense consists of the following:



Three months ended June 30,	U.S. Plans					Non-U.S. Plans						Total
(dollars in thousands)	2017			2016		2017			2016			2017			2016
Service cost	$	96		$	199	$	—		$	1		$	96		$	200
Interest cost	471			652		11			12			482			664
Amortization of unrecognized:
Prior service cost (credit)	(51		)	35		—			—			(51		)	35
Actuarial loss / (gain)	(154		)	20		(13		)	(11		)	(167		)	9
Non-pension postretirement benefit expense	$	362		$	906	$	(2	)	$	2		$	360		$	908

Six months ended June 30,	U.S. Plans					Non-U.S. Plans						Total
(dollars in thousands)	2017			2016		2017			2016			2017			2016
Service cost	$	316		$	398	$	—		$	1		$	316		$	399
Interest cost	1,052			1,304		22			24			1,074			1,328
Amortization of unrecognized:
Prior service cost (credit)	(101		)	70		—			—			(101		)	70
Actuarial loss / (gain)	(129		)	40		(26		)	(22		)	(155		)	18
Non-pension postretirement benefit expense	$	1,138		$	1,812	$	(4	)	$	3		$	1,134		$	1,815

Our 2017 estimate of non-pension cash payments is $5.0 million, and we have paid $1.0 million and $1.6 million for the three months and six months ended June 30, 2017, respectively.