Derivative underlying hedge percent.

No definition available.

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- Definition

Number of outstanding contracts.

+ References

No definition available.

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- 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 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 825
-SubTopic 10
-Section 50
-Paragraph 10
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- Definition

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

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22(a)(1))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

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- Definition

Nominal volume used to calculate payments on a derivative instrument.

+ References

No definition available.

+ Details

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Period Type:	duration

- Definition

Fixed price related to the price risk swap derivative.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Fair value of all derivative assets designated as fair value hedging instruments.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4B
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+ Details

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- Definition

Fair value of all derivative liabilities designated as fair value hedging instruments.

+ References

+ Details

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- Definition

Amount of loss from the write-down of an asset representing the future economic benefits arising from other assets acquired in a business combination that are not individually identified and separately recognized.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

Amount after tax of reclassification adjustment from accumulated other comprehensive income of accumulated gain (loss) realized from derivative instruments designated and qualifying as the effective portion of cash flow hedges and an entity's share of an equity investee's deferred hedging gain (loss).

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Fair Value Measurements (Narrative) (Details) gal in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2015 USD ($)	Dec. 31, 2016 USD ($) Contract $ / gal gal	Dec. 31, 2015 USD ($) Contract	Dec. 31, 2014 USD ($)
Derivatives Fair Value [Line Items]
Derivative underlying hedge percent		80.00%
Derivative, Nonmonetary Notional Amount, Volume \| gal		7.6
Fair value hedge assets		$ 2,293,000
Fair value hedge liabilities			$ 4,388,000
Reclassification of derivative gains to earnings-net of tax		(30,000)		$ 332,000
Impairment of goodwill		0	$ 2,750,000
7.375% Senior Notes Due In 2019 [Member]
Derivatives Fair Value [Line Items]
Debt instrument, face amount		$ 275,000,000
Stated interest rate		7.375%
Maturity date		Feb. 01, 2019
7.375% Senior Notes Due In 2019 [Member] \| Fair Value, Inputs, Level 1 [Member]
Derivatives Fair Value [Line Items]
Fair value of debt		$ 272,250,000
Terra Contracting Services [Member]
Derivatives Fair Value [Line Items]
Impairment of goodwill	$ 2,750,000
Minimum [Member]
Derivatives Fair Value [Line Items]
Fixed price range \| $ / gal		1.25
Maximum [Member]
Derivatives Fair Value [Line Items]
Fixed price range \| $ / gal		1.69
Foreign Exchange Contract [Member]
Derivatives Fair Value [Line Items]
Number of outstanding contracts \| Contract		0	0