Description of Business (Liquidity and Capital Resources) (Details) $ / shares in Units, shares in Millions			3 Months Ended		12 Months Ended
	Nov. 10, 2015	Jun. 15, 2015 USD ($) $ / shares shares	Dec. 31, 2015 USD ($) letter_of_credit	Dec. 31, 2014 USD ($)	Sep. 30, 2015 USD ($)	Feb. 04, 2016 USD ($)	Apr. 17, 2015 USD ($)	Apr. 16, 2015 USD ($)	Jan. 02, 2015 USD ($)	Dec. 10, 2014 USD ($)	Dec. 09, 2014 USD ($)	Oct. 22, 2014 USD ($)	Sep. 30, 2014 USD ($)	Sep. 17, 2014 USD ($)
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Shares acquired (in shares) | shares		6.9
Average cost per share (in usd per share) | $ / shares		$ 6.55
Repurchases of common stock		$ 45,000,000
Repurchase costs		$ 700,000
Cash and cash equivalents			$ 115,520,000	$ 147,576,000	$ 111,885,000								$ 20,687,000
Working capital			128,400,000
Net income			987,000	$ 56,128,000
London Interbank Offered Rate (LIBOR) [Member] | Seventh Amendment [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Basis spread on variable rate	2.50%
Photovoltaics Business [Member] | Photovoltaics [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset purchase agreement, selling price										$ 150,000,000				$ 150,000,000
Working capital adjustment					$ 100,000
Digital Products Business [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Asset purchase agreement, selling price												$ 17,500,000
Asset sale, promissory note, principal amount								$ 15,500,000	$ 1,500,000
Accrued interest on note receivable							$ 200,000
Revolving Credit Facility [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-term line of credit			0
Revolving Credit Facility [Member] | Subsequent Event [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Long-term line of credit						$ 0
Sixth Amendment [Member] | Revolving Credit Facility [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Line of credit facility, maximum borrowing capacity										$ 15,000,000.00
LIBOR Rate Loan [Member] | Revolving Credit Facility [Member]
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Line of credit facility, maximum borrowing capacity											$ 35,000,000
Standby letters of credit, total amount outstanding			$ 700,000
Number of standby letters of credit outstanding | letter_of_credit			2
Remaining borrowing capacity			$ 7,400,000