Business Combination, Contingent Consideration Arrangements, Payment to Option Holder, Percentage of EBITDA

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- Definition

Business Combination, Contingent Consideration, Liability for Payments to Option Holder, Current

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- Definition

Business Combination, Contingent Consideration, Liability for Payments to Option Holder, Noncurrent

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- Definition

Debt Security, Interest Rate, Stated Percentage

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- Definition

Fair Value, Discount Amount, Available for sales securities

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Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques, Unobservable Inputs, Rate, Percentage

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- Definition

Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 25
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=75030427&loc=d3e22054-111558

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 5
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=82897076&loc=d3e27232-111563

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=82896770&loc=d3e26610-111562

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Amount of investment in debt and equity securities categorized neither as trading securities nor held-to-maturity securities and intended be sold or mature one year or operating cycle, if longer.

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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.

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Fair Value Measurements (Narrative-Balances Measured at Fair Value) (Details) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
	Dec. 20, 2011	Jun. 30, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment available for sale		$ 15,100	$ 17,300
Available-for-sale Securities, Current		500	500
Fair Value, Discount Amount, Available for sales securities		2,900	2,900
Business Combination, Contingent Consideration, Liability for Payments to Option Holder, Current		900	800
Business Combination, Contingent Consideration, Liability for Payments to Option Holder, Noncurrent		1,700	2,100
Fair Value, Measurements, Nonrecurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment available for sale		20,000
Fair Value, Measurements, Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment available for sale		$ 15,591	17,752
Debt Security, Interest Rate, Stated Percentage		7.50%
Fair Value, Measurements, Recurring [Member] \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investment available for sale		$ 15,591	$ 17,752
Available-for-sale Securities [Member] \| Discount Rate [Member] \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques, Unobservable Inputs, Rate, Percentage		11.279%	9.637%
Kansas Star [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Business Combination, Contingent Consideration Arrangements, Payment to Option Holder, Percentage of EBITDA	1.00%
Contingent Payments \| Discount Rate [Member] \| Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques, Unobservable Inputs, Rate, Percentage		11.00%	9.20%