Lease Accounting (Maturity of Lease Liabilities) (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jan. 01, 2019
Operating Leased Assets [Line Items]
Remainder of 2019	$ 10,999
2020	39,876
2021	30,184
2022	25,911
2023	23,093
Thereafter	175,106
Total Lease Payments	305,169
Less: Interest	(123,917)
Total Lease Liability	181,252	$ 204,364
Transportation Equipment
Operating Leased Assets [Line Items]
Remainder of 2019	7,208
2020	26,386
2021	20,313
2022	18,060
2023	17,077
Thereafter	43,619
Total Lease Payments	132,663
Less: Interest	(25,391)
Total Lease Liability	107,272
Office Space & Equipment
Operating Leased Assets [Line Items]
Remainder of 2019	1,037
2020	4,107
2021	3,151
2022	2,441
2023	667
Thereafter	2,402
Total Lease Payments	13,805
Less: Interest	(1,792)
Total Lease Liability	12,013
Facilities and Equipment
Operating Leased Assets [Line Items]
Remainder of 2019	2,754
2020	9,383
2021	6,720
2022	5,410
2023	5,349
Thereafter	129,085
Total Lease Payments	158,701
Less: Interest	(96,734)
Total Lease Liability	$ 61,967