Lease Accounting (Maturity of Lease Liabilities) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019
Operating Leased Assets [Line Items]
2019	$ 24,844
2020	39,448
2021	29,944
2022	25,766
2023	23,026
Thereafter	175,011
Total Lease Payments	318,039
Less: Interest	(130,310)
Total Lease Liability	187,729	$ 204,364
Transportation Equipment
Operating Leased Assets [Line Items]
2019	16,213
2020	25,996
2021	20,137
2022	17,980
2023	17,077
Thereafter	43,619
Total Lease Payments	141,022
Less: Interest	(29,195)
Total Lease Liability	111,827
Office Space & Equipment
Operating Leased Assets [Line Items]
2019	2,412
2020	4,069
2021	3,087
2022	2,376
2023	600
Thereafter	2,307
Total Lease Payments	14,851
Less: Interest	(2,264)
Total Lease Liability	12,587
Facilities and Equipment
Operating Leased Assets [Line Items]
2019	6,219
2020	9,383
2021	6,720
2022	5,410
2023	5,349
Thereafter	129,085
Total Lease Payments	162,166
Less: Interest	(98,851)
Total Lease Liability	$ 63,315