Property, plant and equipment and assets held for lease (Tables)

12 Months Ended

Dec. 31, 2015

Schedule of depreciation expense

Depreciation expense for each of the three years ending December 31, 2015 is summarized below (in millions).

	2015		2014		2013
Insurance and other	$	1,680	$	1,632	$	1,691
Railroad, utilities and energy		4,383		3,981		3,232
Finance and financial products		610		602		495
	$	6,673	$	6,215	$	5,418

Insurance and Other [Member]

Schedule of property, plant and equipment

A summary of property, plant and equipment of our insurance and other businesses follows (in millions).

	Ranges of estimated useful life		December 31,
			2015			2014
Land		—	$	1,689		$	1,171
Buildings and improvements		2 – 40 years		7,329			6,600
Machinery and equipment		3 – 25 years		17,054			16,413
Furniture, fixtures and other		1 – 30 years		3,545			3,136
				29,617			27,320
Accumulated depreciation				(14,077	)		(13,167	)
			$	15,540		$	14,153

Railroad, Utilities and Energy [Member]

Schedule of property, plant and equipment

A summary of property, plant and equipment of our railroad and our utilities and energy businesses follows (in millions).

	Ranges of estimated useful life	December 31,
		2015			2014
Railroad:
Land	—	$	6,037		$	5,983
Track structure and other roadway	7 –100 years		45,967			42,588
Locomotives, freight cars and other equipment	6 – 40 years		11,320			9,493
Construction in progress	—		1,031			1,292
			64,355			59,356
Accumulated depreciation			(4,845	)		(3,550	)
		$	59,510		$	55,806
Utilities and energy:
Utility generation, transmission and distribution systems	5 – 80 years	$	69,248		$	64,645
Interstate natural gas pipeline assets	3 – 80 years		6,755			6,660
Independent power plants and other assets	3 – 30 years		5,626			5,035
Construction in progress	—		2,627			5,194
			84,256			81,534
Accumulated depreciation			(23,487	)		(22,286	)
		$	60,769		$	59,248

Finance and Financial Products [Member]

Schedule of property, plant and equipment

Assets held for lease and property, plant and equipment of our finance and financial products businesses are summarized below (in millions).

	Ranges of estimated useful life	December 31,
		2015			2014
Assets held for lease	5 – 30 years	$	11,317		$	9,810
Land	—		220			227
Buildings, machinery and other	3 – 50 years		1,207			1,179
			12,744			11,216
Accumulated depreciation			(3,397	)		(3,179	)
		$	9,347		$	8,037