Business Segments (Tables)

12 Months Ended

Dec. 31, 2015

Business Segments [Abstract]

Schedule of Disclosure on Geographic Areas, Long-Lived Assets in Individual Foreign Countries by Country [Table Text Block]

Geographic information
Net sales by geographic location is the following:
Year Ended December 31,	2015		2014		2013
(Thousands of dollars)
Net sales:
U.S.	$	177,198	$	261,478	$	286,380
Mexico	550,748		483,969		503,184
Consolidated net sales	$	727,946	$	745,447	$	789,564

Long Lived Assets
Long-lived assets includes property, plant and equipment, net, by geographic location as follows:
December 31,	2015		2014
(Thousands of dollars)
Property, plant and equipment, net:
U.S.	$	44,274	$	55,120
Mexico	190,372		199,915
Consolidated property, plant and equipment, net	$	234,646	$	255,035

Schedule of Revenue from External Customers and Long-Lived Assets, by Geographical Areas [Table Text Block]

Geographic information
Net sales by geographic location is the following:
Year Ended December 31,	2015		2014		2013
(Thousands of dollars)
Net sales:
U.S.	$	177,198	$	261,478	$	286,380
Mexico	550,748		483,969		503,184
Consolidated net sales	$	727,946	$	745,447	$	789,564