Represents debt conversion converted instrument shares issued for basis principal.

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Represents debt conversion principal amount of senior notes as basis for conversion rate.

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Percentage points added to the reference rate to compute the variable base rate on the debt instrument.

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Debt Instrument, Convertible, Business Days

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Debt Instrument, Convertible Percentage

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Debt Instrument, Convertible, Trading Day Threshold

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Represents the minimum amount of credit facility acceleration of payments more than other indebtedness.

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Line of Credit Facility, Fixed Charge Coverage Ratio, Amount

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Line of Credit Facility, Maximum Borrowing Capacity, Increased Maximum

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Fair value portion of borrowing which can be exchanged for a specified number of another security at the option of the issuer or the holder, for example, but not limited to, the entity's common stock.

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Percentage points added to the reference rate to compute the variable rate on the debt instrument.

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The price per share of the conversion feature embedded in the debt instrument.

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Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instrument must exceed threshold percentage for specified number of trading days to trigger conversion feature.

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Threshold number of specified trading days that common stock price to conversion price of convertible debt instruments must exceed threshold percentage within a specified consecutive trading period to trigger conversion feature.

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Face (par) amount of debt instrument at time of issuance.

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Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

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Contractual interest rate for funds borrowed, under the debt agreement.

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Amount, after accumulated amortization, of debt discount.

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Weighted average interest rate of debt outstanding.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

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Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

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Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

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The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

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Amount after unamortized (discount) premium and debt issuance costs of long-term debt classified as noncurrent and excluding amounts to be repaid within one year or the normal operating cycle, if longer. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

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Amount of cash and cash equivalents restricted as to withdrawal or usage, classified as current. Cash includes, but is not limited to, currency on hand, demand deposits with banks or financial institutions, and other accounts with general characteristics of demand deposits. Cash equivalents include, but are not limited to, short-term, highly liquid investments that are both readily convertible to known amounts of cash and so near their maturity that they present insignificant risk of changes in value because of changes in interest rates.

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Carrying value as of the balance sheet date, including the current and noncurrent portions, of collateralized debt obligations (with maturities initially due after one year or beyond the operating cycle, if longer). Such obligations include mortgage loans, chattel loans, and any other borrowings secured by assets of the borrower.

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Financing Arrangements and Fair Value of Financial Instruments (Details Textual)	1 Months Ended	3 Months Ended	12 Months Ended
	May 31, 2016	Mar. 31, 2019 USD ($) $ / shares	Dec. 31, 2018 USD ($) trading_day shares	Oct. 31, 2017 USD ($)	May 12, 2016 USD ($)
Conversion price percentage			130.00%
Business day period			5 days
Consecutive trading day period			5 days
Percent threshold last reported sale price			98.00%
Long-term debt, excluding current maturities		$ 179,604,000	$ 159,225,000
Current debt		1,955,000	2,522,000
Restricted cash and cash equivalents, current		6,200,000
Foreign Operations
Current debt		1,591,000	$ 1,137,000
Restricted cash and cash equivalents, current		$ 2,000,000
Senior notes
Debt instrument, convertible, threshold trading days \| trading_day			20
Debt instrument, convertible, threshold consecutive trading days \| trading_day			30
Debt conversion, principal amount as basis for conversion rate			$ 1,000
Debt conversion, converted shares for basis principal (shares) \| shares			107.1381
Interest rate, effective percentage		11.30%
Convertible Notes due 2021 \| Senior notes
Debt instrument, face amount		$ 100,000,000
Interest rate, stated percentage			4.00%
Debt instrument, convertible, conversion price (in dollars per share) \| $ / shares		$ 9.33
Convertible debt, fair value		$ 121,000,000	$ 120,900,000
ABL Facility \| Federal Funds Rate
Base rate basis spread on variable rate	0.50%
ABL Facility \| London Interbank Offered Rate (LIBOR)
Base rate basis spread on variable rate	1.00%
Basis spread on variable rate		1.75%
ABL Facility \| Base Rate
Basis spread on variable rate		0.75%
ABL Facility \| Minimum \| London Interbank Offered Rate (LIBOR)
Basis spread on variable rate	1.75%
ABL Facility \| Minimum \| Base Rate
Basis spread on variable rate	0.75%
ABL Facility \| Maximum \| London Interbank Offered Rate (LIBOR)
Basis spread on variable rate	2.75%
ABL Facility \| Maximum \| Base Rate
Basis spread on variable rate	1.75%
ABL Facility \| Revolving credit facility
Maximum borrowing capacity		$ 174,738,000		$ 200,000,000
Maximum borrowing capacity, maximum				$ 275,000,000
Secured Debt		95,000,000
Remaining borrowing capacity		$ 79,700,000
Fixed charge coverage ratio, amount					$ 22,500,000.0
Debt, weighted average interest rate			4.20%
Unused capacity, commitment fee percentage		0.25%
Covenant terms acceleration of other indebtedness					$ 25,000,000
ABL Facility \| Revolving credit facility \| Minimum
Unused capacity, commitment fee percentage		0.25%
ABL Facility \| Revolving credit facility \| Maximum
Unused capacity, commitment fee percentage		0.375%
Credit Agreement
Letters of credit outstanding, amount		$ 5,700,000
Credit Agreement \| Foreign Operations
Letters of credit outstanding, amount		38,100,000
Convertible debt, debt component
Debt issuance cost		1,700,000
Long-term debt, excluding current maturities		83,600,000
Unamortized debt discount		$ 14,700,000