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Valuation and Qualifying Accounts (Narrative) (Details) - USD ($) $ in Thousands | 12 Months Ended
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Dec. 31, 2016 | Dec. 31, 2015
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Receivables aging period | 60 days |
Accounts receivable reserve period | 90 days |
Allowance for doubtful accounts | $ 2,501 | $ 3,484
Reserves for sales discounts | 13,488 | 15,094
Inventory obsolescence reserves | $ 7,262 | 9,675
Inventory usage period | 3 years |
Inventory reserve percentage | 100.00% |
Product warranty accrual period of expenses used in calculation | 12 months |
Product warranty accrual period for sales used in calculation | 12 months |
Warranty | $ 5,262 | $ 5,566
Parts |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Product warranty period | 90 days |
Minimum |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Sales discount percentage of customers who qualify for each program that discount available | 90.00% |
Product warranty accrual lag period | 90 days |
Maximum |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Sales discount percentage of customers who qualify for each program that discount available | 95.00% |
Product warranty accrual lag period | 6 months |
Maximum | Wholegood Units |  |
Accounts, Notes, Loans and Financing Receivable [Line Items] |  |
Product warranty period | 1 year |

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- Definition For an unclassified balance sheet, a valuation allowance for receivables due a company that are expected to be uncollectible. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=66008989&loc=d3e5074-111524 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.4) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Carrying value as of the balance sheet date of obligations incurred through that date and payable for estimated claims under standard and extended warranty protection rights granted to customers. For classified balance sheets, represents the current portion of the liabilities (due within one year or within the normal operating cycle if longer). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 25 -Paragraph 5 -URI http://asc.fasb.org/extlink&oid=68070138&loc=d3e11281-110244 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 7 -URI http://asc.fasb.org/extlink&oid=68068213&loc=d3e12524-110249 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.20) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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