Debt Instrument, Cash Redemption Price

No definition available.

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- Definition

Debt instrument option common stock closing sales price as percentage of conversion price.

+ References

No definition available.

+ Details

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- Definition

Debt instrument option number of consecutive trading days during which trading price per thousand principal amount was less than specified percentage.

+ References

No definition available.

+ Details

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- Definition

Debt instrument option number of consecutive trading days in which trading price per thousand principal amount was less than specified criteria.

+ References

No definition available.

+ Details

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- Definition

Percentage Of Principal Amount And Accrued And Unpaid Interest For Repurchase Of Debt

+ References

No definition available.

+ Details

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- Definition

Percentage Threshold Closing Sale Price Of Common Stock Higher Than Conversion Price

+ References

No definition available.

+ Details

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- Definition

Principal Amount, Convertible Debenture

+ References

No definition available.

+ Details

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- Definition

Redemption Rate Of Debt Instrument Demanded By Holder Under Change In Business Control

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Amount of noncash expense included in interest expense to amortize debt discount and premium associated with the related debt instruments. Excludes amortization of financing costs. Alternate captions include noncash interest expense.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

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-Section 45

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 8

-Article 5

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- Definition

The carrying amount of the equity component of convertible debt which may be settled in cash upon conversion.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 20

-Section 50

-Paragraph 4

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031897-161870

+ Details

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Balance Type:	credit
Period Type:	instant

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 20

-Section 50

-Paragraph 5

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=6928298&loc=SL6031898-161870

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- Definition

Ratio applied to the conversion of debt instrument into equity with equity shares divided by debt principal amount.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 505

-SubTopic 10

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-Paragraph 3

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-Topic 210

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-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(5))

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Conversion Rate

-URI http://asc.fasb.org/extlink&oid=6509012

+ Details

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- Definition

Threshold period of specified consecutive trading days within which common stock price to conversion price of convertible debt instruments must exceed threshold percentage for a specified number of trading days to trigger conversion feature, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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- Definition

Minimum percentage of common stock price to conversion price of convertible debt instruments to determine eligibility of conversion.

+ References

No definition available.

+ Details

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- Definition

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.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 30

-Section 45

-Paragraph 2

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+ Details

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Balance Type:	credit
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- Definition

Fair value portion of debt instrument payable, including, but not limited to, notes payable and loans payable.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 825

-SubTopic 10

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-Paragraph 10

-Subparagraph (a)

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- Definition

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

+ References

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-Publisher FASB

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-Topic 835

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-Number 210

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-Subparagraph (SX 210.5-02.22(a)(1))

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- Definition

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

+ References

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

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-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(1))

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- Details

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- Definition

The amount of debt discount that was originally recognized at the issuance of the instrument that has yet to be amortized.

+ References

+ Details

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- Definition

Carrying amount of long-term debt, net of unamortized discount or premium, including current and noncurrent amounts. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 16

-Article 7

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-Subparagraph (SX 210.5-02.22)

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-Subparagraph (SX 210.9-03.16)

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- Definition

Price of a single share of a number of saleable stocks of a company.

+ References

No definition available.

+ Details

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Convertible Debentures and Credit Arrangements - Convertible Senior Debentures Narrative (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015 D	Mar. 31, 2014	Nov. 30, 2012
Convertible Senior Debentures due 2018 [Member]
Debt Instrument [Line Items]
Aggregate face value of convertible senior debentures	$ 55,000,000		$ 55,000,000.0
Interest rate on debentures			5.25%
Number of trading days	20
Consecutive trading days	30 days
Threshold percentage of stock trigger	130.00%
Number of consecutive trading days during which the trading price per $1,000 principal amount for at least five days was less than 98% of the product of the closing sale price per share of Company common stock multiplied by the conversion rate on each such trading day (in days)	5 days
Number of days after five consecutive trading days in which the trading price per $1,000 principal amount was less than 98% of the product of the closing sale price per share of Company common stock multiplied by the conversion rate on each such trading day (in days)	5 days
Principal amount of convertible debentures	1,000
Closing price is percentage of conversion price	98.00%
Conversion rate of common stock (in shares)	55.17
Conversion price (in dollars per share)	$ 18.13
Closing price for common stock	$ 18.08
Sales price of common stock to conversion price	140.00%
Debentures redemption price	100.00%
Change in control due to debentures redemption	50.00%
Percentage of principal amount and accrued and unpaid interest for repurchase of debt	100.00%
Fair value of debentures outstanding	65,900,000
Gross carrying amount of equity component	6,400,000
Unamortized discount	4,200,000
Carrying value of liability component	50,800,000
Amortization of debt discount (premium)	$ 300,000	$ 300,000
Debt instrument, interest rate, effective percentage	8.70%
Convertible Senior Debentures due 2014 [Member]
Debt Instrument [Line Items]
Interest rate on debentures			10.125%