Acquisitions and Discontinued Operations - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	0 Months Ended	3 Months Ended		9 Months Ended		3 Months Ended
	Dec. 20, 2013	Mar. 31, 2014 Trust	Mar. 31, 2013	Sep. 30, 2013	Dec. 31, 2013	Mar. 31, 2014 Education Loans [Member] TDRs	Mar. 31, 2014 Level 3 [Member]	Dec. 31, 2013 Level 3 [Member]	Mar. 31, 2013 Level 3 [Member]	Mar. 31, 2014 Victory Capital Management [Member] Level 3 [Member]	Dec. 31, 2013 Mortgage Servicing Rights [Member]	Jun. 30, 2013 Mortgage Servicing Rights [Member]	Mar. 31, 2014 Segment, Discontinued Operations [Member]	Dec. 31, 2013 Segment, Discontinued Operations [Member]	Sep. 30, 2013 Segment, Discontinued Operations [Member]	Mar. 31, 2013 Segment, Discontinued Operations [Member]	Dec. 31, 2009 Segment, Discontinued Operations [Member] Trust
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Fair value of mortgage servicing rights					$ 3						$ 120	$ 117
Principal and interest advances					216
Investment recorded						15
Allowance for loan held as investment		834	893		848	1							34	39		49
Number of TDRs						1,097
Number of outstanding securitization trusts																	10
Economic interest or risk of loss associated with education loan securitization trusts													96
Fair value of loans and securities in securitization trusts after tax loss															48
Loans sold	147	21	57
Gain on sale of loan	3	15	29
Loans purchased		136
Loans at fair value		143	154		147
Number of outstanding securitizations trusts		3
After tax gain on sale of subsidiary		6		92
Cash portion in gain				72
Total assets on a recurring basis at fair value		$ 14	$ 46		$ 30		$ 14	$ 30	$ 44	$ 28