Shareholders' Equity (Tables)

9 Months Ended

Sep. 30, 2018

Shareholders' Equity [Abstract]

Changes in accumulated other comprehensive loss

	Three Months Ended September 30,
	2018						2017
	Total		Defined benefit pension plans		Other post- employment benefit plans		Total		Defined benefit pension plans		Other post- employment benefit plans
Balance, beginning of period	$	(24,617)	$	(25,099)	$	482	$	(39,195)	$	(39,588)	$	393
Amortization		158		168		(10)		5,967		5,986		(19)
Actuarial gains		—		—		—		3,648		3,648		—
Balance, end of period	$	(24,459)	$	(24,931)	$	472	$	(29,580)	$	(29,954)	$	374

	Nine Months Ended September 30,
	2018						2017
	Total		Defined benefit pension plans		Other post- employment benefit plans		Total		Defined benefit pension plans		Other post- employment benefit plans
Balance, beginning of period	$	(24,932)	$	(25,434)	$	502	$	(39,308)	$	(39,737)	$	429
Amortization		473		503		(30)		6,080		6,135		(55)
Actuarial gains		—		—		—		3,648		3,648		—
Balance, end of period	$	(24,459)	$	(24,931)	$	472	$	(29,580)	$	(29,954)	$	374