Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2016

Accounting Policies [Abstract]

Property, Plant and Equipment [Table Text Block]

Classification	Expected Useful Life
Computer equipment	3 to 5 years
Production machinery and equipment	7 to 10 years
Buildings	25 years

PROPERTY, PLANT AND EQUIPMENT

December 31,	2016			2015
(Dollars in thousands)
Land and buildings	$	67,915		$	73,803
Machinery and equipment	485,185			486,612
Leasehold improvements and others	4,868			4,204
Construction in progress	26,301			20,455
	584,269			585,074
Accumulated depreciation	(356,866		)	(350,428		)
Property, plant and equipment, net	$	227,403		$	234,646

Pre-Production Costs and Deferred Revenue Related to Long-Term Supply Arrangements [Table Text Block]

The following tables summarize the unamortized customer-owned tooling costs included in our other non-current assets, and the deferred tooling revenues included in accrued expenses and other non-current liabilities:

December 31,	2016			2015
(Dollars in Thousands)
Customer-Owned Tooling Costs
Preproduction costs	$	78,299		$	73,095
Accumulated amortization	(65,100		)	(58,632		)
Net preproduction costs	$	13,199		$	14,463
Deferred Tooling Revenue
Accrued expenses	$	5,419		$	2,908
Other non-current liabilities	2,593			1,266
Total deferred tooling revenue	$	8,012		$	4,174

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

Year Ended December 31,	2016		2015		2014
(Dollars in thousands, except per share amounts)
Basic Earnings Per Share
Reported net income	$	41,381	$	23,944	$	8,803
Weighted average shares outstanding	25,439		26,599		26,908
Basic earnings per share	$	1.63	$	0.90	$	0.33
Diluted Earnings Per Share
Reported net income	$	41,381	$	23,944	$	8,803
Weighted average shares outstanding	25,439		26,599		26,908
Weighted average dilutive stock options	100		34		112
Weighted average shares outstanding - diluted	25,539		26,633		27,020
Diluted earnings per share	$	1.62	$	0.90	$	0.33