Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2017

Goodwill is identified by segment as follows (in millions):


	Wellbore Technologies			Completion & Production Solutions			Rig Technologies			Total
Balance at December 31, 2015	$	2,874		$	1,997		$	2,109		$	6,980

Goodwill acquired and adjusted during period		4			70			—			74
Impairment		—			—			(972	)		(972	)
Currency translation adjustments		(4	)		(9	)		(2	)		(15	)

Balance at December 31, 2016	$	2,874		$	2,058		$	1,135		$	6,067

Goodwill acquired and adjusted during period		37			41			11			89
Currency translation adjustments		45			23			3			71

Balance at December 31, 2017 (1)	$	2,956		$	2,122		$	1,149		$	6,227

(1)	Accumulated goodwill impairment was $2,457 million as of December 31, 2017.

The net book values of identified intangible assets are identified by segment as follows (in millions):


	Wellbore Technologies			Completion & Production Solutions			Rig Technologies			Total
Balance at December 31, 2015	$	2,254		$	1,296		$	299		$	3,849

Additions to intangible assets		15			9			—			24
Amortization		(205	)		(106	)		(22	)		(333	)
Currency translation adjustments		—			(8	)		(2	)		(10	)

Balance at December 31, 2016	$	2,064		$	1,191		$	275		$	3,530

Additions to intangible assets		18			41			2			61
Amortization		(208	)		(108	)		(23	)		(339	)
Currency translation adjustments		9			36			4			49

Balance at December 31, 2017	$	1,883		$	1,160		$	258		$	3,301

Identified intangible assets by major classification consist of the following (in millions):


	Gross		Accumulated Amortization			Net Book Value
December 31, 2016:

Customer relationships	$	4,024	$	(1,874	)	$	2,150
Trademarks		878		(290	)		588
Patents		585		(345	)		240
Indefinite-lived trade names		384		—			384
Other		463		(295	)		168

Total identified intangibles	$	6,334	$	(2,804	)	$	3,530

December 31, 2017:

Customer relationships	$	4,074	$	(2,118	)	$	1,956
Trademarks		885		(317	)		568
Patents		602		(384	)		218
Indefinite-lived trade names		384		—			384
Other		499		(324	)		175

Total identified intangibles	$	6,444	$	(3,143	)	$	3,301

The changes in the carrying amount of service and product warranties are as follows (in millions):


Balance at December 31, 2015	$	244

Net provisions for warranties issued during the year		50
Amounts incurred		(127	)
Currency translation adjustments and other		5

Balance at December 31, 2016	$	172

Net provisions for warranties issued during the year		46
Amounts incurred		(86	)
Currency translation adjustments and other		3

Balance at December 31, 2017	$	135

The following table sets forth the computation of weighted average basic and diluted shares outstanding (in millions, except per share data):


	Years Ended December 31,
	2017			2016			2015
Numerator:
Net loss attributable to Company	$	(237	)	$	(2,412	)	$	(769	)

Denominator:
Basic—weighted average common shares outstanding		377			376			387
Dilutive effect of employee stock options and other unvested stock awards		—			—			—

Diluted outstanding shares		377			376			387

Basic loss attributable to Company per share	$	(0.63	)	$	(6.41	)	$	(1.99	)

Diluted loss attributable to Company per share	$	(0.63	)	$	(6.41	)	$	(1.99	)

Cash dividends per share	$	0.20		$	0.61		$	1.84