Income Taxes (Provision for Income Taxes from Continuing Operations Differs from the Federal Statutory Rate) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Statutory rate	$ 17,494	$ 12,985	$ (29,664)
Intangible asset impairment	341	0	26,637
State taxes, less federal effect	3,033	1,845	606
Non-deductible expenses	685	284	94
Non-deductible expenses	556	2	233
Federal tax credits	(439)	(242)	(255)
Uncertain tax positions	(154)	(344)	(169)
Foreign rate differential	(677)	(6)	(311)
Worthless stock deduction	(868)	0	0
Domestic manufacturer's deduction	(1,363)	(795)	(60)
Intercompany debt discharge	(2,389)	0	0
Other	45	(105)	(69)
Provision for income taxes	$ 16,264	$ 13,624	$ (2,958)
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Statutory rate	35.00%	35.00%	35.00%
Intangible asset impairment	0.70%	0.00%	(31.40%)
State taxes, less federal effect	6.10%	5.00%	(0.70%)
Change in valuation allowance	1.40%	0.70%	(0.10%)
Non-deductible expenses	1.10%	0.00%	(0.30%)
Federal tax credits	(0.90%)	(0.70%)	0.30%
Uncertain tax positions	(0.30%)	(0.90%)	0.20%
Foreign rate differential	(1.40%)	0.00%	0.40%
Worthless stock deduction	(1.70%)	0.00%	0.00%
Domestic manufacturer's deduction	(2.70%)	(2.10%)	0.10%
Intercompany debt discharge	(4.80%)	0.00%	0.00%
Other	0.00%	(0.30%)	0.00%
Effective income tax rate, percentage	32.50%	36.70%	3.50%