Related Party Transactions - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Mar. 31, 2012	Jun. 30, 2009
Related Party Transaction [Line Items]
Percentage of Processing Business Bancorp retained	39.00%		49.00%
Percentage of Processing Business sold to Advent for cash and warrants			51.00%
Gain on Vantiv, Inc. IPO		$ 115
Units held after Vantiv, Inc. IPO and exercise of underwriters' warrant	84
Incremental Share Purchase Option	20
After tax gain on Vantiv, Inc. IPO		$ 75
Voting power percentage	18.50%
Class B common shares held in Vantiv, Inc.	84

The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 159

-Paragraph 18

-Subparagraph f

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Accounting Principles Board Opinion (APB)

-Number 18

-Paragraph 20

-Subparagraph a (1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 323

-SubTopic 10

-Section 50

-Paragraph 3

-Subparagraph (a)(1)

-URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571

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