Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2015

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Balances in the Allowance Accounts

The balances in the allowance accounts at December 31, 2015 and 2014 were as follows (table in millions):

	December 31,
	2015		2014
Current	$	90	$	72
Non-current (included in other assets, net)	2		2
	$	92	$	74

Estimated Useful Lives of the Assets

Depreciation commences upon placing the asset in service and is recognized on a straight-line basis over the estimated useful lives of the assets, as follows:

Furniture and fixtures	5-10 years
Equipment and software	2-10 years
Improvements	5-31 years
Buildings	15-51 years

Property, plant and equipment consist of (table in millions):

	December 31, 2015			December 31, 2014
Furniture and fixtures	$	283		$	255
Equipment and software	7,378			6,684
Buildings and improvements	2,373			2,308
Land	171			162
Building construction in progress	83			134
	10,288			9,543
Accumulated depreciation	(6,438		)	(5,777		)
	$	3,850		$	3,766