Summary Of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Accounting Policies [Abstract]

Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]

	Year ended December 31,
	2013		2014
As reported:
Transportation and terminals revenue	$	1,138,328	$	1,402,638
Costs and expenses:
Operating	$	346,070	$	444,272
Effect of adjustments:
Transportation and terminals revenue	$	50,124	$	56,629
Costs and expenses:
Operating	$	50,124	$	56,629
As revised:
Transportation and terminals revenue	$	1,188,452	$	1,459,267
Costs and expenses:
Operating	$	396,194	$	500,901