Unaudited Quarterly Financial Data Supplemental Consolidated Financial Information (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Quarterly Financial Information Disclosure [Abstract]
Interest income	$ 195,384	$ 185,240	$ 177,983	$ 171,014	$ 168,168	$ 161,958	$ 159,818	$ 158,774	$ 729,621		$ 648,718		$ 565,388
Interest expense	(8,386)	(8,144)	(7,902)	(7,845)	(7,605)	(7,528)	(7,884)	(7,837)	(32,277)		(30,854)		(39,111)
Net interest income	186,998	177,096	170,081	163,169	160,563	154,430	151,934	150,937	697,344		617,864		526,277
Reduction of (provision for) loan losses	(28,670)	(10,638)	(18,572)	(5,813)	(15,014)	(6,788)	(7,999)	(14,529)
Noninterest income	238,713	257,650	98,239	78,604	126,688	69,139	80,426	59,293	673,206		335,546		382,332
Noninterest expense	(168,850)	(160,524)	(143,292)	(149,014)	(143,049)	(135,171)	(135,766)	(132,012)	(621,680)	[1]	(545,998)	[1]	(500,628)	[1]
Income (loss) before income tax expense	228,191	263,584	106,456	86,946	129,188	81,610	88,595	63,689
Income tax expense	35,285	47,404	29,968	26,401	29,526	28,470	31,517	23,756	(139,058)		(113,269)		(119,087)
Net income before noncontrolling interests	192,906	216,180	76,488	60,545	99,662	53,140	57,078	39,933	546,119		249,813		282,793
Comprehensive income attributable to noncontrolling interests	(134,149)	(148,559)	(27,904)	(19,654)	(49,241)	(10,851)	(9,475)	(5,143)	(330,266)		(74,710)		(110,891)
Net income available to common stockholders	$ 58,757	$ 67,621	$ 48,584	$ 40,891	$ 50,421	$ 42,289	$ 47,603	$ 34,790	$ 215,853		$ 175,103		$ 171,902
Earnings per common share—basic	$ 1.29	$ 1.48	$ 1.08	$ 0.91	$ 1.13	$ 0.95	$ 1.08	$ 0.79	$ 4.76		$ 3.96		$ 4.00
Earnings per common share—diluted	$ 1.27	$ 1.46	$ 1.06	$ 0.90	$ 1.12	$ 0.94	$ 1.06	$ 0.78	$ 4.70		$ 3.91		$ 3.94

[1] The Global Commercial Bank segment includes direct depreciation and amortization of $21.3 million, $16.3 million and $12.0 million for 2013, 2012 and 2011, respectively.