Note 16 - Fair Value Measurements (Details) - Assets and Liabilities Measured at Fair Value on a Recurring Basis (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Securities available-for-sale
Securities Available-for-Sale	$ 1,586,668	$ 1,291,480
Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Securities Available-for-Sale	465,917	526,165
Total Assets	465,917	526,165
Liabilities
Total Liabilities	0	0
Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities Available-for-Sale	1,120,751	765,315
Total Assets	1,131,869	772,942
Liabilities
Total Liabilities	6,140	1,588
Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Securities Available-for-Sale		0
Total Assets	30	104
Liabilities
Total Liabilities	0	0
Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Securities Available-for-Sale	1,586,668	1,291,480
Total Assets	1,597,816	1,299,211
Liabilities
Total Liabilities	6,140	1,588
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Securities Available-for-Sale	460,193	509,971
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Securities Available-for-Sale		0
US Treasury Securities [Member] | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Securities Available-for-Sale	460,193	509,971
US Treasury Securities [Member]
Securities available-for-sale
Securities Available-for-Sale	460,193	509,971
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities Available-for-Sale	952,815	416,694
Collateralized Mortgage Backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Collateralized Mortgage Backed Securities [Member] | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Securities Available-for-Sale	952,815	416,694
Collateralized Mortgage Backed Securities [Member]
Securities available-for-sale
Securities Available-for-Sale	952,814	416,694
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities Available-for-Sale	6,106	10,168
Collateralized Mortgage Obligations [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Collateralized Mortgage Obligations [Member] | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Securities Available-for-Sale	6,106	10,168
Collateralized Mortgage Obligations [Member]
Securities available-for-sale
Securities Available-for-Sale	6,106	10,168
Asset-backed Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Asset-backed Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities Available-for-Sale	123	141
Asset-backed Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Asset-backed Securities [Member] | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Securities Available-for-Sale	123	141
Asset-backed Securities [Member]
Securities available-for-sale
Securities Available-for-Sale	123	141
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities Available-for-Sale	150,304	335,977
Corporate Debt Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Corporate Debt Securities [Member] | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Securities Available-for-Sale	150,304	335,977
Corporate Debt Securities [Member]
Securities available-for-sale
Securities Available-for-Sale	150,304	335,977
Mutual Funds Member | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Securities Available-for-Sale	5,724	6,079
Mutual Funds Member | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Mutual Funds Member | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Mutual Funds Member | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Securities Available-for-Sale	5,724	6,079
Mutual Funds Member
Securities available-for-sale
Securities Available-for-Sale	5,725	6,079
Preferred Stock Of Government Sponsored Entities Member | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Preferred Stock Of Government Sponsored Entities Member | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities Available-for-Sale	11,403	2,335
Preferred Stock Of Government Sponsored Entities Member | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Preferred Stock Of Government Sponsored Entities Member | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Securities Available-for-Sale	11,403	2,335
Preferred Stock Of Government Sponsored Entities Member
Securities available-for-sale
Securities Available-for-Sale	11,403	2,335
Trust Preferred Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Securities Available-for-Sale	465,917	10,115
Trust Preferred Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Securities Available-for-Sale	1,120,751	0
Trust Preferred Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Securities Available-for-Sale	0	0
Trust Preferred Securities [Member] | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Securities Available-for-Sale	1,586,668	10,115
Trust Preferred Securities [Member]
Securities available-for-sale
Securities Available-for-Sale		10,115
Trading Securities Member | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Total Assets	0
Trading Securities Member | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Total Assets	4,936	4,703
Trading Securities Member | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Total Assets	0	0
Trading Securities Member | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Total Assets	4,936	4,703
Warrant [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Total Assets	0	0
Warrant [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Total Assets	0	0
Warrant [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Total Assets	30	104
Warrant [Member] | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Total Assets	30	104
Option Contracts Member | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Total Assets	0	0
Liabilities
Total Liabilities		0
Option Contracts Member | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Total Assets	0	0
Liabilities
Total Liabilities		2
Option Contracts Member | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Total Assets	0	0
Liabilities
Total Liabilities		0
Option Contracts Member | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Total Assets	0	0
Liabilities
Total Liabilities		2
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Securities available-for-sale
Total Assets	0	0
Liabilities
Total Liabilities	0	0
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Securities available-for-sale
Total Assets	6,182	2,924
Liabilities
Total Liabilities	6,140	1,586
Foreign Exchange Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Securities available-for-sale
Total Assets	0	0
Liabilities
Total Liabilities	0	0
Foreign Exchange Contract [Member] | Estimate of Fair Value Measurement [Member]
Securities available-for-sale
Total Assets	6,182	2,924
Liabilities
Total Liabilities	$ 6,140	$ 1,586