Other Intangible Assets, Net (Tables)

12 Months Ended

Dec. 31, 2014

Goodwill and Intangible Assets Disclosure [Abstract]

Summary of major classes of amortizable intangible assets

	December 31, 2014							December 31, 2013
	Gross carrying amount		Accumulated amortization			Net carrying amount		Gross carrying amount		Accumulated amortization			Net carrying amount
	(millions)
Client relationships	$	689	$	(316	)	$	373	$	671	$	(326	)	$	345
Management contracts	71		(1		)	70		—		—			—
Other	11		(4		)	7		14		(6		)	8
Total amortizable intangible assets	$	771	$	(321	)	$	450	$	685	$	(332	)	$	353

Estimated aggregate amortization of intangible assets for each of the next five years

	(millions)
2015	$	57
2016	51
2017	46
2018	41
2019	37
Thereafter	218
Total	$	450