Debt (Narrative) (Details)	9 Months Ended
Sep. 30, 2015 USD ($)
Line of Credit Facility [Line Items]
Unsecured revolving line of credit	$ 50,000,000
Outstanding borrowing on line of credit	$ 25,000,000
Ratio of consolidated indebtedness to earnings before interest, taxes, depreciation and amortization, maximum allowed	3.25
Ratio of consolidated earnings before interest, taxes, depreciation and amortization expense, minimum allowed	3.00
Line of Credit [Member]
Line of Credit Facility [Line Items]
Weighted average interest rate	1.33%
Interest expense	$ 53,000
Minimum [Member]
Line of Credit Facility [Line Items]
Quarterly commitment fee	0.175%
Maximum [Member]
Line of Credit Facility [Line Items]
Quarterly commitment fee	0.30%
Base Rate Determined In Accordance With Loan Agreement [Member] \| Minimum [Member]
Line of Credit Facility [Line Items]
Variable interest rate spread	0.00%
Base Rate Determined In Accordance With Loan Agreement [Member] \| Maximum [Member]
Line of Credit Facility [Line Items]
Variable interest rate spread	0.50%
London Interbank Offered Rate [Member \| Minimum [Member]
Line of Credit Facility [Line Items]
Variable interest rate spread	1.125%
London Interbank Offered Rate [Member \| Maximum [Member]
Line of Credit Facility [Line Items]
Variable interest rate spread	2.00%
During Event Of Default [Member]
Line of Credit Facility [Line Items]
Variable interest rate spread	2.00%

Loan agreement, quarterly commitment fee paid on unused portion of line of credit, percentage.

No definition available.

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- Definition

Loan agreement, ratio of consolidated earnings before interest, taxes, depreciation and amortization expense, minimum allowed.

+ References

No definition available.

+ Details

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- Definition

Loan agreement, ratio of consolidated indebtedness to earnings before interest, taxes, depreciation and amortization, maximum allowed.

+ References

No definition available.

+ Details

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

Weighted average interest rate of debt outstanding.

+ References

No definition available.

+ Details

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- Definition

Amount of the cost of borrowed funds accounted for as interest expense.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 835

-SubTopic 20

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6450988&loc=d3e26243-108391

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.9)

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 04

-Paragraph 9

-Article 9

+ Details

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- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

+ Details

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Balance Type:	credit
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

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.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

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