Property, plant and equipment (Tables)

3 Months Ended

Mar. 31, 2012

Insurance and Other [Member]

Property, plant and equipment

Property, plant and equipment of our insurance and other businesses is comprised of the following (in millions).

	Ranges of estimated useful life	March 31, 2012			December 31, 2011
Land	—	$	942		$	940
Buildings and improvements	3 – 40  years		5,442			5,429
Machinery and equipment	3 – 25  years		13,794			13,589
Furniture, fixtures and other	2 – 20  years		2,562			2,397
Assets held for lease	12 – 30  years		6,256			5,997
			28,996			28,352
Accumulated depreciation			(10,595	)		(10,175	)
		$	18,401		$	18,177

Railroad, Utilities and Energy [Member]

Property, plant and equipment

Property, plant and equipment of our railroad, utilities and energy businesses is comprised of the following (in millions).

	Ranges of estimated  useful life	March 31, 2012			December 31, 2011
Railroad:
Land	—	$	5,929		$	5,925
Track structure and other roadway	5 – 100 years		37,043			36,760
Locomotives, freight cars and other equipment	5 – 37 years		5,820			5,533
Construction in progress	—		941			885
Utilities and energy:
Utility generation, distribution and transmission system	5 – 80 years		40,608			40,180
Interstate pipeline assets	3 – 80 years		6,253			6,245
Independent power plants and other assets	3 – 30 years		1,114			1,106
Construction in progress	—		2,045			1,559
			99,753			98,193
Accumulated depreciation			(16,427	)		(15,979	)
		$	83,326		$	82,214