Property, plant and equipment (Tables)

3 Months Ended

Mar. 31, 2013

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		March 31,			December 31,
			2013			2012
Land		—	$	1,058		$	1,048
Buildings and improvements		2 – 40 years		6,074			6,074
Machinery and equipment		3 – 20 years		15,509			15,436
Furniture, fixtures and other		2 – 20 years		2,863			2,736
Assets held for lease		12 – 30 years		6,844			6,731
				32,348			32,025
Accumulated depreciation				(13,200	)		(12,837	)
			$	19,148		$	19,188

Railroad, Utilities and Energy [Member]

Schedule of 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,			December 31,
			2013			2012
Railroad:
Land		—	$	5,957		$	5,950
Track structure and other roadway		5 – 100 years		38,488			38,255
Locomotives, freight cars and other equipment		5 – 37 years		6,657			6,528
Construction in progress		—		1,014			963
Utilities and energy:
Utility generation, distribution and transmission system		5 – 80 years		42,490			42,682
Interstate pipeline assets		3 – 80 years		6,371			6,354
Independent power plants and other assets		3 – 30 years		2,110			1,860
Construction in progress		—		2,859			2,647
				105,946			105,239
Accumulated depreciation				(17,827	)		(17,555	)
			$	88,119		$	87,684