Leases (Financing leases) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Ending January 1,
2021	$ 6,194
2022	3,774
Total future payments	9,968
Less payment related to:
Maintenance	2,336
Interest	253
Finance lease obligations	7,379	$ 11,380
Current portion of finance leases	4,164
Total long-term finance lease payments	$ 3,215

Amount equal to the present value (the principal) at the beginning of the lease term of minimum lease payments during the lease term (excluding that portion of the payments representing executory costs such as insurance, maintenance, and taxes to be paid by the lessor, together with any profit thereon) net of payments or other amounts applied to the principal through the balance sheet date.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 10
-Section S99
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-URI http://asc.fasb.org/extlink&oid=84164817&loc=d3e45280-112737

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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- Definition

Amounts to be paid by lessee to lessor for maintenance, insurance, and tax expenses related to the leased asset.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 30
-Section 50
-Paragraph 1
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- Definition

Amount necessary to reduce net minimum lease payments to present value for capital leases.

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Present value of lessee's discounted obligation for lease payments from finance lease, classified as current.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
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Present value of lessee's discounted obligation for lease payments from finance lease, classified as noncurrent.

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Amount of lessee's undiscounted obligation for lease payments for finance lease.

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Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
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-SubTopic 20
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- Definition

Amount of lessee's undiscounted obligation for lease payments for finance lease, due in next fiscal year following latest fiscal year.

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Amount of lessee's undiscounted obligation for lease payments for finance lease, due in second fiscal year following latest fiscal year.

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