Cash and Cash Equivalents (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	[1],[2]	Dec. 31, 2014	[1],[2]
Cash and Cash Equivalents [Abstract]
Cash and due from banks	$ 1,574,966	$ 1,372,743
Securities purchased under agreements to resell	288,421	125,391
Other short-term investment securities	5,125	5,123
Total cash and cash equivalents	$ 1,868,512	$ 1,503,257	$ 1,263,846		$ 1,811,014

[1] Amounts for the three months ended March 31, 2015, have been revised to reflect the retrospective application of new accounting guidance adopted in the second quarter of 2015 related to our consolidated variable interest entities (ASU 2015-02).

[2] Cash and cash equivalents at March 31, 2015 and December 31, 2014 included $9.3 million and $15.0 million, respectively, recognized in assets held-for-sale in conjunction with the SVBIF sale transaction.