Geographic Information Table (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Schedule Of Geographical Information [Line Items]
Revenues from external customers	$ 8,420	[1]	$ 7,964	[1]	$ 7,363	[1]
Long-lived assets	1,351	[2]	1,316	[2]	1,261	[2]
Total assets	4,010		3,830		3,608
United States
Schedule Of Geographical Information [Line Items]
Revenues from external customers	3,348	[1]	3,144	[1]	2,975	[1]
Long-lived assets	473	[2]	448	[2]	429	[2]
Total assets	1,710		1,552		1,521
Germany
Schedule Of Geographical Information [Line Items]
Revenues from external customers	1,079	[1]	875	[1]	661	[1]
Long-lived assets	192	[2]	158	[2]	139	[2]
Total assets	683		602		448
Canada
Schedule Of Geographical Information [Line Items]
Revenues from external customers	955	[1]	941	[1]	817	[1]
Long-lived assets	113	[2]	120	[2]	115	[2]
Total assets	319		358		344
CHINA
Schedule Of Geographical Information [Line Items]
Revenues from external customers	423	[1]	397	[1]	374	[1]
Long-lived assets	34	[2]	31	[2]	31	[2]
Total assets	156		126		120
Mexico
Schedule Of Geographical Information [Line Items]
Revenues from external customers	413	[1]	387	[1]	389
Long-lived assets	52		59		57
Total assets	164		182		168
Other Foreign Countries [Member]
Schedule Of Geographical Information [Line Items]
Revenues from external customers	2,202	[1],[3]	2,220	[1],[3]	2,147	[1],[3]
Long-lived assets	487	[2],[3]	500	[2],[3]	490	[2],[3]
Total assets	1,133	[3]	1,200	[3]	1,187	[3]
Intersegment Eliminations [Member]
Schedule Of Geographical Information [Line Items]
Revenues from external customers	0		0		0
Long-lived assets	0
Reclass & Elims
Schedule Of Geographical Information [Line Items]
Total assets	$ (155)		$ (190)		$ (180)

[1] Revenues are attributed to countries based on location of the shipper.

[2] Long-lived assets include all long-term assets except goodwill, intangibles and deferred tax assets.

[3] Revenues from external customers and long-lived assets for individual foreign countries other than China, Germany, Mexico, and Canada are not material.