Segment Information (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Jun. 29, 2011
Results of operations and selected financial information
Net interest income (expense)	$ 40,832	$ 40,218	$ 122,518	$ 115,513
Noninterest income	22,116	20,117	65,917	57,526
Income before taxes	20,250	18,191	60,716	52,087
Maximum limit to include the preferred securities in Tier 1 Capital	5,836,751	5,472,306	5,836,751	5,472,306	5,608,825	10,000,000
Metropolitan Banks [Member]
Results of operations and selected financial information
Net interest income (expense)	13,267	13,167	39,784	37,650
Noninterest income	2,840	2,979	8,193	8,491
Income before taxes	8,302	7,612	24,954	22,492
Maximum limit to include the preferred securities in Tier 1 Capital	1,892,444	1,660,756	1,892,444	1,660,756	1,738,426
Community Banks [Member]
Results of operations and selected financial information
Net interest income (expense)	26,302	26,518	79,317	75,576
Noninterest income	11,153	10,607	32,009	29,292
Income before taxes	15,234	14,867	45,433	41,703
Maximum limit to include the preferred securities in Tier 1 Capital	3,745,727	3,615,387	3,745,727	3,615,387	3,660,239
Other Financial Services [Member]
Results of operations and selected financial information
Net interest income (expense)	1,777	1,620	5,211	5,349
Noninterest income	7,404	5,845	23,482	17,448
Income before taxes	3,266	2,217	11,664	7,849
Maximum limit to include the preferred securities in Tier 1 Capital	126,704	134,984	126,704	134,984	153,872
Executive, Operations and Support [Member]
Results of operations and selected financial information
Net interest income (expense)	(514)	(1,087)	(1,794)	(3,062)
Noninterest income	14,881	13,897	43,507	38,139
Income before taxes	7,463	6,557	19,682	15,647
Maximum limit to include the preferred securities in Tier 1 Capital	636,853	612,535	636,853	612,535	602,577
Eliminations [Member]
Results of operations and selected financial information
Noninterest income	(14,162)	(13,211)	(41,274)	(35,844)
Income before taxes	(14,015)	(13,062)	(41,017)	(35,604)
Maximum limit to include the preferred securities in Tier 1 Capital	$ (564,977)	$ (551,356)	$ (564,977)	$ (551,356)	$ (546,289)