Debt - Maturities (Details) $ in Thousands	Dec. 31, 2018 USD ($) instrument
Aggregate maturities of obligations under capital leases
January 2019 - December 2019	$ 2,830
January 2020 - December 2020	2,276
January 2021 - December 2021	19
Obligations under capital leases	$ 5,125
Notes payable to finance companies for insurance
Notes payable
Number of outstanding notes payable \| instrument	2
Aggregate principal amount outstanding	$ 1,680
Interest rate (as a percent)	3.80%
Notes payable to commercial banks
Notes payable
Aggregate principal amount outstanding	$ 5,975
Interest rate (as a percent)	5.00%
Obligations under capital leases \| Minimum
Notes payable
Interest rate (as a percent)	4.65%
Obligations under capital leases \| Maximum
Notes payable
Interest rate (as a percent)	4.93%

The number of outstanding notes payable.

No definition available.

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- Definition

Amount of minimum lease payments for capital leases.

+ References

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 840
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- Definition

Amount of minimum lease payments for capital leases due in the next fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of minimum lease payments for capital leases due in the third fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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Amount of minimum lease payments for capital leases due in the second fiscal year following the latest fiscal year. Excludes interim and annual periods when interim periods are reported on a rolling approach, from latest balance sheet date.

+ References

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- Definition

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

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. 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/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 470
-SubTopic 20
-Section 50
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- References

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