Property, Plant And Equipment

3 Months Ended

Mar. 31, 2017

Property, Plant And Equipment [Abstract]

Property, Plant And Equipment

(5)  Property, Plant and Equipment:

Property, plant and equipment, net is as follows:

($ in millions)	March 31, 2017		December 31, 2016
Property, plant and equipment	$	25,626	$	25,541
Less:  Accumulated depreciation		(11,010)		(10,639)
Property, plant and equipment, net	$	14,616	$	14,902

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

	For the three months ended March 31,
($ in millions)	2017		2016
Depreciation expense	$	376	$	240

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 March 2017, we sold and leased back certain properties, generating $70 million in net proceeds. We have deferred $52 million in gains, which are included in Other liabilities on our consolidated balance sheet as of March 31, 2017 and are being amortized over the related lease terms.