Property, Plant And Equipment

9 Months Ended

Sep. 30, 2017

Property, Plant And Equipment [Abstract]

(5) Property, Plant and Equipment:

Property, plant and equipment, net is as follows:



($ in millions)	September 30, 2017		December 31, 2016

Property, plant and equipment	$	26,124	$	25,541
Less: Accumulated depreciation		(11,749)		(10,639)
Property, plant and equipment, net	$	14,375	$	14,902

Depreciation expense is principally based on the composite group method. Depreciation expense was as follows:


	For the three months ended September 30,				For the nine months ended September 30,
($ in millions)	2017		2016		2017		2016

Depreciation expense	$	376	$	323	$	1,131	$	1,009

We adopted new estimated remaining useful lives for certain plant assets as of October 1, 2016, as a result of an annual independent study of the estimated remaining useful lives of our plant assets, with an insignificant impact to depreciation expense.

In 2017, we sold certain properties, generating $102 million in net proceeds, of which $97 million relates to property subject to leasebacks. For these properties, we have deferred $66 million in related gains that will be amortized over the related lease terms of two years. For the nine months ended September 30, 2017, amortization of these deferred gains totaled $14 million, which are included in “Selling, general and administrative expenses” on our consolidated income statement. We have remaining deferred gain balances of $52 million, which are included in “Other liabilities”.