|12 Months Ended|
Dec. 31, 2015
|Components of inventory||
Inventories consisted of the following (dollars in millions):
Tabular disclosure of the carrying amount as of the balance sheet date of merchandise, goods, commodities, or supplies held for future sale or to be used in manufacturing, servicing or production process.
Reference 1: http://www.xbrl.org/2003/role/presentationRef