Property, plant and equipment (Tables)

12 Months Ended

Dec. 31, 2012

Insurance and Other [Member]

Schedule of 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		December 31,
			2012			2011
Land		—	$	1,048		$	940
Buildings and improvements		2 – 40 years		6,074			5,429
Machinery and equipment		3 – 20 years		15,436			13,589
Furniture, fixtures and other		2 – 20 years		2,736			2,397
Assets held for lease		12 – 30 years		6,731			5,997
				32,025			28,352
Accumulated depreciation				(12,837	)		(10,175	)
			$	19,188		$	18,177

Railroad, Utilities and Energy [Member]

Schedule of property, plant and equipment

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

	Ranges of estimated useful life	December 31,
		2012			2011
Railroad:
Land	—	$	5,950		$	5,925
Track structure and other roadway	5 – 100 years		38,255			36,760
Locomotives, freight cars and other equipment	5 – 37 years		6,528			5,533
Construction in progress	—		963			885
Utilities and energy:
Utility generation, distribution and transmission system	5 – 80 years		42,682			40,180
Interstate pipeline assets	3 – 80 years		6,354			6,245
Independent power plants and other assets	3 – 30 years		1,860			1,106
Construction in progress	—		2,647			1,559
			105,239			98,193
Accumulated depreciation			(17,555	)		(15,979	)
		$	87,684		$	82,214