Fair Value Measurements Fair Value by Balance Sheet Grouping (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2012		Dec. 31, 2011
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities	$ 190,615		$ 189,518
Held to maturity securities	196,382		194,350
Loans held for sale	3,178,597		2,725,286
Loans Held-for-sale, Fair Value Disclosure	1,105,985		777,280
Deposits	10,803,743		10,265,763
Other borrowings	2,503,636		1,257,879
Trust preferred securities	103,750		103,750
Loans Receivable, Allowance	73,233		73,999
Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to maturity securities	0
Loans Held-for-sale, Fair Value Disclosure	0	[1]
Loans held for investment	0	[2]
Time deposits	0
Other borrowings	0
Trust preferred securities	0
Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to maturity securities	196,382
Loans Held-for-sale, Fair Value Disclosure	2,171,991	[1]
Loans held for investment	0	[2]
Time deposits	2,930,669
Other borrowings	2,545,991
Trust preferred securities	0
Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to maturity securities	0
Loans Held-for-sale, Fair Value Disclosure	0	[1]
Loans held for investment	7,111,132	[2]
Time deposits	0
Other borrowings	0
Trust preferred securities	78,274
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held-to-maturity Securities	190,615		189,518
Loans held for sale	2,072,612	[1]	2,725,286
Loans held for investment	7,030,992	[2]	5,856,781	[2]
Time deposits	2,894,148
Deposits			10,265,763
Other borrowings	2,503,636		1,257,879
Trust preferred securities	103,750		103,750
Estimate of Fair Value, Fair Value Disclosure [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Held to maturity securities	196,382		194,350
Loans Held-for-sale, Fair Value Disclosure	2,171,991	[1]	2,811,917
Loans Receivable, Fair Value Disclosure	7,111,132	[2]	5,862,053	[2]
Time deposits	2,930,669
Deposits, Fair Value Disclosure			10,299,977
Other borrowings	2,545,991		1,215,209
Trust preferred securities	78,274		71,597
Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Held-for-sale, Fair Value Disclosure	1,105,985		777,280
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Held-for-sale, Fair Value Disclosure	0		0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Held-for-sale, Fair Value Disclosure	1,105,985		761,818
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Held-for-sale, Fair Value Disclosure	0		15,462
Aggregate Fair Value Under Fair Value Option [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Held-for-sale, Fair Value Disclosure	1,105,985		777,280
Aggregate Fair Value Under Fair Value Option [Member] | Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Loans Held-for-sale, Fair Value Disclosure	$ 1,105,985

[1] The carrying value of loans held for sale excludes $1,105,985 in loans measured at fair value on a recurring basis as of June 30, 2012.

[2] (2)The carrying value of loans held for investment is net of the allowance for loan loss of $73,233 and $73,999 as of June 30, 2012 and December 31, 2011, respectively. In addition, the carrying values exclude $677,045 and $584,735 of lease financing receivables as of June 30, 2012 and December 31, 2011, respectively.