Retirement Plans (Tables) - USD ($)
$ in Thousands

3 Months Ended

6 Months Ended

Jun. 30, 2017

Jun. 30, 2016

Jun. 30, 2017

Jun. 30, 2016

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Net Pension Income or Postretirement Expense

Net pension income for our domestic and foreign plans was as follows:

	Three Months Ended						Six Months Ended
	June 30,			June 30,			June 30,			June 30,
	2017			2016			2017			2016
Net pension income	$	(491	)	$	(402	)	$	(924	)	$	(794	)

The components of net pension (income) expense for our domestic and foreign plans include the following: 

	DomesticPension Plans						Foreign Pension Plans
	Three Months Ended						Three Months Ended
	June 30,			June 30,			June 30,			June 30,
	2017			2016			2017			2016
Service cost	$	—		$	22		$	12		$	13
Interest cost	2,068			2,756			9			11
Expected return on plan assets (1)	(4,060		)	(4,744		)	(5		)	7
Amortization of loss	1,446			1,498			39			35
(Income) expense, net	$	(546	)	$	(468	)	$	55		$	66

(1) Expected return on plan assets is net of expected investment expenses and certain administrative expenses.

	DomesticPension Plans					Foreign Pension Plans
	Six Months Ended					Six Months Ended
	June 30,		June 30,			June 30,			June 30,
	2017		2016			2017			2016
Service cost	—		$	44		$	24		$	25
Interest cost	4,136		5,512			17			22
Expected return on plan assets (1)	(8,121	)	(9,488		)	(10		)	14
Amortization of loss	2,892		2,996			77			69
Other cost due to retirement	61		12			—			—
(Income) expense, net	(1,032	)	(924		)	108			130

(1) Expected return on plan assets is net of expected investment expenses and certain administrative expenses.

Net post-retirement expense for our other post-retirement plan includes the following components:

	Three Months Ended						Six Months Ended
	June 30,			June 30,			June 30,			June 30,
	2017			2016			2017			2016
Service cost	$	—		$	1		$	1		$	2
Interest cost	40			52			80			104
Amortization of gain	(25		)	(37		)	(50		)	(75		)
Post-retirement expense	$	15		$	16		$	31		$	31

United States Pension Plan of US Entity [Member]

Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]

Service cost

$ 0

$ 22

$ 0

$ 44