Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Increase (decrease) in accumulated other comprehensive income (loss) [Roll Forward]
Balance at the beginning of the year	$ (13,394)	$ (11,523)	$ (4,393)
Unrealized gains (losses)	744	(5,093)	(2,798)
Amounts reclassified from accumulated other comprehensive income (loss)	2,844	4,774	2,786
Tax effect	(1,137)	(1,878)	(1,095)
Unrecognized amounts from defined benefit pension plans	(2,032)	538	(9,923)
Tax effect	813	(212)	3,900
Net of tax amount	1,232	(1,871)	(7,130)
Balance at the end of the year	(12,162)	(13,394)	(11,523)
Foreign Currency Translation Adjustments
Increase (decrease) in accumulated other comprehensive income (loss) [Roll Forward]
Balance at the beginning of the year	(6,244)	(1,151)	1,647
Unrealized gains (losses)	744	(5,093)	(2,798)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0
Tax effect	0	0	0
Unrecognized amounts from defined benefit pension plans	0	0	0
Tax effect	0	0	0
Net of tax amount	744	(5,093)	(2,798)
Balance at the end of the year	(5,500)	(6,244)	(1,151)
Defined Benefit Pension Plans
Increase (decrease) in accumulated other comprehensive income (loss) [Roll Forward]
Balance at the beginning of the year	(7,150)	(10,372)	(6,040)
Unrealized gains (losses)	0	0	0
Amounts reclassified from accumulated other comprehensive income (loss)	2,844	4,774	2,786
Tax effect	(1,137)	(1,878)	(1,095)
Unrecognized amounts from defined benefit pension plans	(2,032)	538	(9,923)
Tax effect	813	(212)	3,900
Net of tax amount	488	3,222	(4,332)
Balance at the end of the year	$ (6,662)	$ (7,150)	$ (10,372)