Lease Accounting (Maturity of Lease Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Jan. 01, 2019
Operating Leased Assets [Line Items]
2020	$ 39,783
2021	30,141
2022	25,858
2023	23,163
2024	21,845
Thereafter	152,783
Total Lease Payments	293,573
Less: Interest	(120,257)
Present value of operating lease liabilities	173,316	$ 204,364
Transportation Equipment
Operating Leased Assets [Line Items]
2020	26,355
2021	20,282
2022	18,022
2023	17,160
2024	16,355
Thereafter	27,163
Total Lease Payments	125,337
Less: Interest	(23,428)
Present value of operating lease liabilities	101,909
Office Space & Equipment
Operating Leased Assets [Line Items]
2020	4,119
2021	3,163
2022	2,453
2023	678
2024	689
Thereafter	1,723
Total Lease Payments	12,825
Less: Interest	(1,619)
Present value of operating lease liabilities	11,206
Facilities and Equipment
Operating Leased Assets [Line Items]
2020	9,309
2021	6,696
2022	5,383
2023	5,325
2024	4,801
Thereafter	123,897
Total Lease Payments	155,411
Less: Interest	(95,210)
Present value of operating lease liabilities	$ 60,201

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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 50
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=77888426&loc=SL77918701-209980

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Amount of lessee's undiscounted obligation for lease payments for operating lease, due after fifth fiscal year following latest fiscal year.

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Amount of lessee's undiscounted obligation for lease payments in excess of discounted obligation for lease payments for operating lease.

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Present value of lessee's discounted obligation for lease payments from operating lease.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 842
-SubTopic 20
-Section 45
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=77888419&loc=SL77918627-209977

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