FAIR VALUE (Fair Value Measurements, Recurring) (Details) (USD $)	Jun. 30, 2014	Dec. 31, 2013
Financial assets:
Available-for-sale investment securities	$ 11,675,042,000	$ 11,646,240,000
Trading securities	125,116,000	0
Retail installment contracts held for investment	1,273,072,000	0
Derivative assets at fair value	251,741,000	222,491,000
Financial liabilities:
Derivative liabilities	287,667,000	239,311,000
US Treasury and government agency securities [Member]
Financial assets:
Available-for-sale investment securities	8,000,000	24,997,000
Corporate debt [Member]
Financial assets:
Available-for-sale investment securities	2,234,349,000	2,218,180,000
Asset-backed securities [Member]
Financial assets:
Available-for-sale investment securities	2,604,661,000	2,732,230,000
Equity securities [Member]
Financial assets:
Available-for-sale investment securities	10,163,000	9,841,000
State and municipal securities [Member]
Financial assets:
Available-for-sale investment securities	1,830,276,000	1,850,149,000
Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets:
Available-for-sale investment securities	10,163,000	9,841,000
Trading securities	0
Loans held for sale	0	0
Mortgage servicing rights	0	0
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Significant Other Observable Inputs (Level 2) [Member]
Financial assets:
Available-for-sale investment securities	10,421,007,000	11,583,459,000
Trading securities	125,116,000
Loans held for sale	290,736,000	128,949,000
Mortgage servicing rights	0	0
Derivative assets at fair value	278,723,000	256,324,000
Financial liabilities:
Derivative liabilities	318,390,000	273,306,000
Significant Unobservable Inputs (Level 3) [Member]
Financial assets:
Available-for-sale investment securities	1,243,872,000	52,940,000
Trading securities	0
Loans held for sale	0	0
Mortgage servicing rights	124,118,000	141,787,000
Derivative assets at fair value	4,102,000	561,000
Financial liabilities:
Derivative liabilities	361,000	397,000
Fair Value [Member]
Financial assets:
Available-for-sale investment securities	11,675,042,000	11,646,240,000
Trading securities	125,116,000
Loans held for sale	290,736,000	128,949,000
Mortgage servicing rights	124,118,000	141,787,000
Derivative assets at fair value	282,825,000	256,885,000
Financial liabilities:
Derivative liabilities	318,751,000	273,703,000
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member]
Financial assets:
Available-for-sale investment securities	10,163,000	9,841,000
Trading securities	0
Retail installment contracts held for investment	0
Loans held for sale	0	0
Mortgage servicing rights	0	0
Total financial assets	10,163,000	9,841,000
Financial liabilities:
Total financial liabilities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage banking interest rate lock commitments [Member]
Financial assets:
Derivative assets at fair value	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Customer related [Member]
Financial assets:
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Foreign exchange [Member]
Financial assets:
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage servicing [Member]
Financial assets:
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest rate cap agreements [Member]
Financial assets:
Derivative assets at fair value	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Other [Member]
Financial assets:
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage banking forward sell commitments [Member]
Financial assets:
Derivative assets at fair value		0
Financial liabilities:
Derivative liabilities	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Total return swap [Member]
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Interest rate swap agreements [Member]
Financial liabilities:
Derivative liabilities	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Option for interest rate cap [Member]
Financial liabilities:
Derivative liabilities	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Fair value [Member]
Financial assets:
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Cash flow [Member]
Financial assets:
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | US Treasury and government agency securities [Member]
Financial assets:
Available-for-sale investment securities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Corporate debt [Member]
Financial assets:
Available-for-sale investment securities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Asset-backed securities [Member]
Financial assets:
Available-for-sale investment securities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Equity securities [Member]
Financial assets:
Available-for-sale investment securities	10,163,000	9,841,000
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | State and municipal securities [Member]
Financial assets:
Available-for-sale investment securities	0	0
Recurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) [Member] | Mortgage backed securities [Member]
Financial assets:
Available-for-sale investment securities	0	0
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member]
Financial assets:
Available-for-sale investment securities	10,421,007,000	11,583,459,000
Trading securities	125,116,000
Retail installment contracts held for investment	0
Loans held for sale	166,616,000	128,949,000
Mortgage servicing rights	0	0
Total financial assets	10,991,462,000	11,968,732,000
Financial liabilities:
Total financial liabilities	318,390,000	273,306,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage banking interest rate lock commitments [Member]
Financial assets:
Derivative assets at fair value	0	0
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Customer related [Member]
Financial assets:
Derivative assets at fair value	214,918,000	225,811,000
Financial liabilities:
Derivative liabilities	184,624,000	198,669,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Foreign exchange [Member]
Financial assets:
Derivative assets at fair value	7,593,000	11,631,000
Financial liabilities:
Derivative liabilities	6,199,000	9,745,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage servicing [Member]
Financial assets:
Derivative assets at fair value	722,000	6,155,000
Financial liabilities:
Derivative liabilities	188,000	488,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest rate cap agreements [Member]
Financial assets:
Derivative assets at fair value	46,631,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Other [Member]
Financial assets:
Derivative assets at fair value	5,902,000	4,750,000
Financial liabilities:
Derivative liabilities	6,727,000	4,099,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage banking forward sell commitments [Member]
Financial assets:
Derivative assets at fair value		2,101,000
Financial liabilities:
Derivative liabilities	3,151,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Total return swap [Member]
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Interest rate swap agreements [Member]
Financial liabilities:
Derivative liabilities	24,240,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Option for interest rate cap [Member]
Financial liabilities:
Derivative liabilities	46,677,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Fair value [Member]
Financial assets:
Derivative assets at fair value	855,000	1,073,000
Financial liabilities:
Derivative liabilities	2,303,000	1,924,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Cash flow [Member]
Financial assets:
Derivative assets at fair value	2,102,000	4,803,000
Financial liabilities:
Derivative liabilities	44,281,000	58,381,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | US Treasury and government agency securities [Member]
Financial assets:
Available-for-sale investment securities	8,000,000	24,997,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Corporate debt [Member]
Financial assets:
Available-for-sale investment securities	2,234,349,000	2,218,180,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Asset-backed securities [Member]
Financial assets:
Available-for-sale investment securities	1,360,789,000	2,679,290,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Equity securities [Member]
Financial assets:
Available-for-sale investment securities	0	0
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | State and municipal securities [Member]
Financial assets:
Available-for-sale investment securities	1,830,276,000	1,850,149,000
Recurring [Member] | Significant Other Observable Inputs (Level 2) [Member] | Mortgage backed securities [Member]
Financial assets:
Available-for-sale investment securities	4,987,593,000	4,810,843,000
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member]
Financial assets:
Available-for-sale investment securities	1,243,872,000	52,940,000
Trading securities	0
Retail installment contracts held for investment	1,273,072,000
Loans held for sale	0	0
Mortgage servicing rights	124,118,000	141,787,000
Total financial assets	2,645,164,000	195,288,000
Financial liabilities:
Total financial liabilities	361,000	397,000
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage banking interest rate lock commitments [Member]
Financial assets:
Derivative assets at fair value	4,092,000	547,000
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Customer related [Member]
Financial assets:
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Foreign exchange [Member]
Financial assets:
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage servicing [Member]
Financial assets:
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest rate cap agreements [Member]
Financial assets:
Derivative assets at fair value	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Other [Member]
Financial assets:
Derivative assets at fair value	10,000	14,000
Financial liabilities:
Derivative liabilities	76,000	112,000
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage banking forward sell commitments [Member]
Financial assets:
Derivative assets at fair value		0
Financial liabilities:
Derivative liabilities	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Total return swap [Member]
Financial liabilities:
Derivative liabilities	285,000	285,000
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Interest rate swap agreements [Member]
Financial liabilities:
Derivative liabilities	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Option for interest rate cap [Member]
Financial liabilities:
Derivative liabilities	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Fair value [Member]
Financial assets:
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Cash flow [Member]
Financial assets:
Derivative assets at fair value	0	0
Financial liabilities:
Derivative liabilities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | US Treasury and government agency securities [Member]
Financial assets:
Available-for-sale investment securities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Corporate debt [Member]
Financial assets:
Available-for-sale investment securities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Asset-backed securities [Member]
Financial assets:
Available-for-sale investment securities	1,243,872,000	52,940,000
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Equity securities [Member]
Financial assets:
Available-for-sale investment securities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | State and municipal securities [Member]
Financial assets:
Available-for-sale investment securities	0	0
Recurring [Member] | Significant Unobservable Inputs (Level 3) [Member] | Mortgage backed securities [Member]
Financial assets:
Available-for-sale investment securities	0	0
Recurring [Member] | Fair Value [Member]
Financial assets:
Available-for-sale investment securities	11,675,042,000	11,646,240,000
Trading securities	125,116,000
Retail installment contracts held for investment	1,273,072,000
Loans held for sale	166,616,000	128,949,000
Mortgage servicing rights	124,118,000	141,787,000
Total financial assets	13,646,789,000	12,173,861,000
Financial liabilities:
Total financial liabilities	318,751,000	273,703,000
Recurring [Member] | Fair Value [Member] | Mortgage banking interest rate lock commitments [Member]
Financial assets:
Derivative assets at fair value	4,092,000	547,000
Recurring [Member] | Fair Value [Member] | Customer related [Member]
Financial assets:
Derivative assets at fair value	214,918,000	225,811,000
Financial liabilities:
Derivative liabilities	184,624,000	198,669,000
Recurring [Member] | Fair Value [Member] | Foreign exchange [Member]
Financial assets:
Derivative assets at fair value	7,593,000	11,631,000
Financial liabilities:
Derivative liabilities	6,199,000	9,745,000
Recurring [Member] | Fair Value [Member] | Mortgage servicing [Member]
Financial assets:
Derivative assets at fair value	722,000	6,155,000
Financial liabilities:
Derivative liabilities	188,000	488,000
Recurring [Member] | Fair Value [Member] | Interest rate cap agreements [Member]
Financial assets:
Derivative assets at fair value	46,631,000
Recurring [Member] | Fair Value [Member] | Other [Member]
Financial assets:
Derivative assets at fair value	5,912,000	4,764,000
Financial liabilities:
Derivative liabilities	6,803,000	4,211,000
Recurring [Member] | Fair Value [Member] | Mortgage banking forward sell commitments [Member]
Financial assets:
Derivative assets at fair value		2,101,000
Financial liabilities:
Derivative liabilities	3,151,000
Recurring [Member] | Fair Value [Member] | Total return swap [Member]
Financial liabilities:
Derivative liabilities	285,000	285,000
Recurring [Member] | Fair Value [Member] | Interest rate swap agreements [Member]
Financial liabilities:
Derivative liabilities	24,240,000
Recurring [Member] | Fair Value [Member] | Option for interest rate cap [Member]
Financial liabilities:
Derivative liabilities	46,677,000
Recurring [Member] | Fair Value [Member] | Fair value [Member]
Financial assets:
Derivative assets at fair value	855,000	1,073,000
Financial liabilities:
Derivative liabilities	2,303,000	1,924,000
Recurring [Member] | Fair Value [Member] | Cash flow [Member]
Financial assets:
Derivative assets at fair value	2,102,000	4,803,000
Financial liabilities:
Derivative liabilities	44,281,000	58,381,000
Recurring [Member] | Fair Value [Member] | US Treasury and government agency securities [Member]
Financial assets:
Available-for-sale investment securities	8,000,000	24,997,000
Recurring [Member] | Fair Value [Member] | Corporate debt [Member]
Financial assets:
Available-for-sale investment securities	2,234,349,000	2,218,180,000
Recurring [Member] | Fair Value [Member] | Asset-backed securities [Member]
Financial assets:
Available-for-sale investment securities	2,604,661,000	2,732,230,000
Recurring [Member] | Fair Value [Member] | Equity securities [Member]
Financial assets:
Available-for-sale investment securities	10,163,000	9,841,000
Recurring [Member] | Fair Value [Member] | State and municipal securities [Member]
Financial assets:
Available-for-sale investment securities	1,830,276,000	1,850,149,000
Recurring [Member] | Fair Value [Member] | Mortgage backed securities [Member]
Financial assets:
Available-for-sale investment securities	$ 4,987,593,000	$ 4,810,843,000