Pension and Non-pension Post-retirement 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 September 30,	U.S. Plans						Non-U.S. Plans						Total
(dollars in thousands)	2017			2016			2017			2016			2017			2016
Service cost	$	979		$	929		$	286		$	313		$	1,265		$	1,242
Interest cost	3,445			3,740			725			663			4,170			4,403
Expected return on plan assets	(5,619		)	(5,757		)	—			—			(5,619		)	(5,757		)
Amortization of unrecognized:
Prior service cost (credit)	59			65			(54		)	(53		)	5			12
Actuarial loss	1,308			1,068			156			412			1,464			1,480
Pension expense	$	172		$	45		$	1,113		$	1,335		$	1,285		$	1,380

Nine months ended September 30,	U.S. Plans						Non-U.S. Plans						Total
(dollars in thousands)	2017			2016			2017			2016			2017			2016
Service cost	$	2,937		$	2,788		$	814		$	948		$	3,751		$	3,736
Interest cost	10,337			11,222			2,063			2,005			12,400			13,227
Expected return on plan assets	(16,859		)	(17,272		)	—			—			(16,859		)	(17,272		)
Amortization of unrecognized:
Prior service cost (credit)	177			197			(153		)	(160		)	24			37
Actuarial loss	3,925			3,204			446			817			4,371			4,021
Settlement charge	—			42			—			170			—			212
Pension expense	$	517		$	181		$	3,170		$	3,780		$	3,687		$	3,961

We have contributed $0.6 million and $2.6 million of cash into our pension plans for the three months and nine months ended September 30, 2017, respectively. Pension contributions for the remainder of 2017 are estimated to be $0.5 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, post-retirement plans cover the hourly and salaried U.S.-based employees of Libbey (excluding those mentioned above). The non-U.S., non-pension, post-retirement plans cover the retirees and active employees of Libbey who are located in Canada. The post-retirement benefit plans are unfunded.

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



Three months ended September 30,	U.S. Plans					Non-U.S. Plans						Total
(dollars in thousands)	2017			2016		2017			2016			2017			2016
Service cost	$	157		$	200	$	—		$	—		$	157		$	200
Interest cost	526			652		10			11			536			663
Amortization of unrecognized:
Prior service cost (credit)	(50		)	35		—			—			(50		)	35
Actuarial loss / (gain)	(65		)	21		(13		)	(10		)	(78		)	11
Non-pension post-retirement benefit expense	$	568		$	908	$	(3	)	$	1		$	565		$	909

Nine months ended September 30,	U.S. Plans					Non-U.S. Plans						Total
(dollars in thousands)	2017			2016		2017			2016			2017			2016
Service cost	$	473		$	598	$	1		$	1		$	474		$	599
Interest cost	1,578			1,956		32			35			1,610			1,991
Amortization of unrecognized:
Prior service cost (credit)	(151		)	105		—			—			(151		)	105
Actuarial loss / (gain)	(194		)	61		(39		)	(32		)	(233		)	29
Non-pension post-retirement benefit expense	$	1,706		$	2,720	$	(6	)	$	4		$	1,700		$	2,724

Our 2017 estimate of non-pension cash payments is $4.0 million, and we have paid $1.0 million and $2.6 million for the three months and nine months ended September 30, 2017, respectively.