Discontinued Operations Summarized results of discontinued operations (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016		Jun. 30, 2015
Discontinued Operations and Disposal Groups [Abstract]
Disposal Group, Including Discontinued Operation, Revenue		$ 0	$ 33,375	$ 29,680		$ 67,063
Disposal Group, Including Discontinued Operation, Cost of Goods Sold, Direct Materials		0	23,291	21,027		47,281
Disposal Group, Including Discontinued Operation, Operating Expense		0	8,336	7,288		16,804
Disposal Group, Including Discontinued Operation, Interest Expense	[1]	0	349	333		731
Discontinued Operation, Income (Loss) from Discontinued Operation, before Income Tax		0	1,399	1,032		2,247
Discontinued Operation, Tax Effect of Gain (Loss) from Disposal of Discontinued Operation		0	556	(3,908)	[2]	869
Discontinued Operation, Gain (Loss) on Disposal of Discontinued Operation, Net of Tax		0	0	2,994		0
Income (Loss) from Discontinued Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		$ 0	$ 843	$ 7,934		$ 1,378

[1] (a)Interest expense was allocated to the discontinued operation based on the debt that was required to be paid as a result of the sale of TPI.

[2] (b) Income tax benefit for the six months ended June 30, 2016 includes $4,207 reversal of valuation allowance resulting from the sale of TPI.