Other assets by major categories (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Line Items]
Net deferred tax assets (net of valuation allowance)	$ 758,347	$ 761,768
Investments under the equity method	221,130	197,006
Bank Owned Life Insurance	0	228,805
Prepaid F D I C Insurance Assessment	0	383
Prepaid Taxes	207,999	91,504
Other prepaid expenses	97,122	67,108
Derivative Asset, Fair Value, Gross Asset	25,850	34,710
Trades receivables from brokers and counterparties	77,618	71,680	85,746
Others	246,753	234,594
Total other assets	$ 1,634,819	$ 1,687,558