Inventories (Tables)

12 Months Ended

Dec. 31, 2018

Inventories [Abstract]

Inventory Amounts by Product Type

Our inventory amounts by product type were as follows at the dates indicated:

	December 31,
	2018		2017
NGLs	$	647.7	$	917.4
Petrochemicals and refined products		264.7		161.5
Crude oil		593.4		516.3
Natural gas		16.3		14.6
Total	$	1,522.1	$	1,609.8

Cost of Sales and Lower of Cost or Market Adjustments

The following table presents our total cost of sales amounts and lower of cost or net realizable value adjustments for the years indicated:

	For the Year Ended December 31,
	2018		2017		2016
Cost of sales (1)	$	26,789.8	$	21,487.0	$	15,710.9
Lower of cost or net realizable value adjustments within cost of sales		11.5		9.1		11.5
(1)   Cost of sales is a component of “Operating costs and expenses,” as presented on our Statements of Consolidated Operations. Fluctuations in these amounts are primarily due to changes in energy commodity prices and sales volumes associated with our marketing activities.