Inventories

Major classes of inventories are as follows:



(in thousands)	March 31, 2018		December 31, 2017		March 31, 2017
Grain	$	541,272	$	505,217	$	443,870
Ethanol and co-products	14,320		11,003		15,549
Plant nutrients and cob products	170,748		126,962		165,584
Retail merchandise	—		—		11,082
Railcar repair parts	5,289		5,521		5,209
	$	731,629	$	648,703	$	641,294

Inventories on the Condensed Consolidated Balance Sheets at March 31, 2018, December 31, 2017 and March 31, 2017 do not include 0.7 million, 1.0 million and 2.7 million bushels of grain, respectively, held in storage for others. The Company does not have title to the grain and is only liable for any deficiencies in grade or shortage of quantity that may arise during the storage period. Management has not experienced historical losses on any deficiencies and does not anticipate material losses in the future.