Segment Reporting (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Activities by Segment [Abstract]
Revenues	$ 949,189	$ 952,435
Segment operating earnings (loss)	10,666	14,701
Depreciation Depletion and Amortization	6,106	5,529
Property and Equipment Additions	7,770	3,903
Segment operating earnings [Abstract]
Segment operating earnings (loss)	10,666	14,701
General and administrative expenses	(2,254)	(2,032)
Operating earnings	8,412	12,669
Interest income	42	38
Interest expense	0	(2)
Earnings from continuing operations before income taxes	8,454	12,705
Identifiable assets by segment [Abstract]
Assets	464,612		448,082
Marketing [Member]
Activities by Segment [Abstract]
Revenues	927,204	931,876
Segment operating earnings (loss)	9,370	13,434
Depreciation Depletion and Amortization	2,269	1,764
Property and Equipment Additions	4,076	1,361
Segment operating earnings [Abstract]
Segment operating earnings (loss)	9,370	13,434
Identifiable assets by segment [Abstract]
Assets	294,928		306,693
Transportation [Member]
Activities by Segment [Abstract]
Revenues	17,649	17,346
Segment operating earnings (loss)	1,175	1,398
Depreciation Depletion and Amortization	1,813	1,736
Property and Equipment Additions	203	145
Segment operating earnings [Abstract]
Segment operating earnings (loss)	1,175	1,398
Identifiable assets by segment [Abstract]
Assets	34,941		34,406
Oil and Gas [Member]
Activities by Segment [Abstract]
Revenues	4,336	3,213
Segment operating earnings (loss)	121	(131)
Depreciation Depletion and Amortization	2,024	2,029
Property and Equipment Additions	3,491	2,397
Segment operating earnings [Abstract]
Segment operating earnings (loss)	121	(131)
Identifiable assets by segment [Abstract]
Assets	37,437		37,093
Other [Member]
Identifiable assets by segment [Abstract]
Assets	$ 97,306		$ 69,890