Premises and Equipment and Other Assets

Premises and Equipment

Premises and equipment are carried at cost, less accumulated depreciation and amortization. As of December 31, 2015 and 2014, the amounts were as follows:



	December 31,
	2015							2014
(Dollars in millions)	Cost		Accumulated Depreciation and Amortization			Net Book Value		Cost		Accumulated Depreciation and Amortization			Net Book Value
Land	$	140	$	—		$	140	$	148	$	—		$	148
Premises	598		(342		)	256		601		(334		)	267
Leasehold improvements	331		(236		)	95		301		(230		)	71
Furniture, fixtures and equipment	671		(554		)	117		682		(547		)	135
Total	$	1,740	$	(1,132	)	$	608	$	1,732	$	(1,111	)	$	621

Rental, depreciation and amortization expenses were as follows:



	For the Years Ended December 31,
(Dollars in millions)	2015		2014		2013
Rental expense of premises	$	129	$	113	$	111
Less: rental income	24		10		9
Net rental expense	$	105	$	103	$	102
Depreciation and amortization of premises and equipment	$	96	$	103	$	110

Future minimum lease payments at December 31, 2015 were as follows:



(Dollars in millions)	2015
Years ending December 31,:
2016	$	128
2017	120
2018	110
2019	95
2020	83
Thereafter	443
Total minimum lease payments	$	979
Minimum rental income due in the future under subleases	$	106

The Company's leases are for land, branch or office space. A majority of the leases provide for the payment of taxes, maintenance, insurance, and certain other expenses applicable to the leased premises. Many of the leases contain extension provisions and escalation clauses. These leases are generally renewable and may in certain cases contain provisions and options to expand or contract space, renew or terminate the lease or purchase the leased premises at predetermined contractual dates. In addition, escalation clauses may exist, which are tied to either a predetermined rate or may change based on a specified percentage increase or the Consumer Price Index.

At December 31, 2015 and 2014, the Company had a liability of $6 million for asset retirement obligations. These obligations include environmental remediation on buildings and the removal of leasehold improvements from leased premises to be vacated in cases where management has sufficient information to estimate the obligation's fair value.

Other Assets

The following table shows the balances of other assets as of December 31, 2015 and 2014.



(Dollars in millions)	December 31, 2015		December 31, 2014
Other investments	$	2,953	$	2,695
Software	364		275
Intangible assets	206		240
OREO	31		36
Other	1,823		1,384
Total other assets	$	5,377	$	4,630