Employee Benefits - Fair Values of Pension Plan Assets by Asset Category (Detail) - USD ($) $ in Millions	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	$ 14
United States Pension Plan of US Entity [Member] | Equity Securities [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	133	$ 128
United States Pension Plan of US Entity [Member] | Equity Securities [Member] | Preferred Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	2	2
United States Pension Plan of US Entity [Member] | Corporate Bonds - U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	90
United States Pension Plan of US Entity [Member] | Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	118	16
United States Pension Plan of US Entity [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	152	5
United States Pension Plan of US Entity [Member] | Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	15	26
Foreign Pension Plan [Member] | Equity Securities [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	15	20
Foreign Pension Plan [Member] | Corporate Bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	26
Foreign Pension Plan [Member] | Government Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	1	1
Foreign Pension Plan [Member] | Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	35	24
Foreign Pension Plan [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	19	2
Foreign Pension Plan [Member] | Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	97	106
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	1,133	869	$ 957
Pension Plans [Member] | Short-term investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	18	21
Pension Plans [Member] | Corporate Bonds - U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		97
Pension Plans [Member] | Corporate Bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		26
Pension Plans [Member] | Government Bonds and Agency Bonds - U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	101	95
Pension Plans [Member] | State and Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	5	6
Pension Plans [Member] | Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	9	101
Pension Plans [Member] | Convertible Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	43	41
Pension Plans [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	79	86
Pension Plans [Member] | Real Assets, Collective Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	95
Pension Plans [Member] | Insurance Investment Contracts and Pooled Separate Accounts [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	14	14
Pension Plans [Member] | Other Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	52	52
Level 1 [Member] | Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	14
Level 1 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	133	128
Level 1 [Member] | United States Pension Plan of US Entity [Member] | Equity Securities [Member] | Preferred Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	2	2
Level 1 [Member] | United States Pension Plan of US Entity [Member] | Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	118	16
Level 1 [Member] | United States Pension Plan of US Entity [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	152	5
Level 1 [Member] | Foreign Pension Plan [Member] | Equity Securities [Member] | Common Stock [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	15	20
Level 1 [Member] | Foreign Pension Plan [Member] | Mutual Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	35	24
Level 1 [Member] | Foreign Pension Plan [Member] | Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	19	2
Level 1 [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	497	197
Level 1 [Member] | Pension Plans [Member] | Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	9
Level 2 [Member] | United States Pension Plan of US Entity [Member] | Corporate Bonds - U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	90
Level 2 [Member] | United States Pension Plan of US Entity [Member] | Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	15	26
Level 2 [Member] | Foreign Pension Plan [Member] | Corporate Bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	26
Level 2 [Member] | Foreign Pension Plan [Member] | Government Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	1	1
Level 2 [Member] | Foreign Pension Plan [Member] | Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	97	106
Level 2 [Member] | Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	570	606
Level 2 [Member] | Pension Plans [Member] | Short-term investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	18	21
Level 2 [Member] | Pension Plans [Member] | Corporate Bonds - U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		97
Level 2 [Member] | Pension Plans [Member] | Corporate Bonds - International [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		26
Level 2 [Member] | Pension Plans [Member] | Government Bonds and Agency Bonds - U.S. [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	101	95
Level 2 [Member] | Pension Plans [Member] | State and Municipal Bonds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	5	6
Level 2 [Member] | Pension Plans [Member] | Real Assets [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value		101
Level 2 [Member] | Pension Plans [Member] | Convertible Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	43	41
Level 2 [Member] | Pension Plans [Member] | Fixed Income Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	79	$ 86
Level 2 [Member] | Pension Plans [Member] | Real Assets, Collective Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Assets at fair value	$ 95