Note 5 - Investments Schedule of Unrealized Losses (Details) $ in Thousands	Jun. 30, 2015 USD ($) security	Dec. 31, 2014 USD ($) security
Continuous Loss Position Less Than Twelve Months
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year | security	174	62
Fair value available-for-sale securities	$ 851,504	$ 144,626
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	$ 20,898	$ 2,379
Continuous Unrealized Loss Position, Twelve Months Or Greater
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year | security	18	2
Fair value available-for-sale securities	$ 50,215	$ 4,482
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 894	$ 154
Continuous Loss Position, Total
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	192	64
Fair value available-for-sale securities	$ 901,719	$ 149,108
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 21,792	$ 2,533
US government and agency securities
Continuous Loss Position Less Than Twelve Months
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year | security		0
Fair value available-for-sale securities		$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss		$ 0
Continuous Unrealized Loss Position, Twelve Months Or Greater
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year | security		1
Fair value available-for-sale securities		$ 3,455
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		$ 6
Continuous Loss Position, Total
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security		1
Fair value available-for-sale securities		$ 3,455
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		$ 6
State and municipal obligations
Continuous Loss Position Less Than Twelve Months
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year | security	1
Fair value available-for-sale securities	$ 5,727
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	$ 2
Continuous Unrealized Loss Position, Twelve Months Or Greater
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year | security	0
Fair value available-for-sale securities	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 0
Continuous Loss Position, Total
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	1
Fair value available-for-sale securities	$ 5,727
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 2
Corporate bonds and notes
Continuous Loss Position Less Than Twelve Months
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year | security	95	24
Fair value available-for-sale securities	$ 408,203	$ 40,917
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	$ 13,528	$ 410
Continuous Unrealized Loss Position, Twelve Months Or Greater
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year | security	7	1
Fair value available-for-sale securities	$ 10,172	$ 1,027
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 407	$ 148
Continuous Loss Position, Total
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	102	25
Fair value available-for-sale securities	$ 418,375	$ 41,944
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 13,935	$ 558
RMBS
Continuous Loss Position Less Than Twelve Months
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year | security	9
Fair value available-for-sale securities	$ 116,631
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	$ 2,115
Continuous Unrealized Loss Position, Twelve Months Or Greater
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year | security	0
Fair value available-for-sale securities	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 0
Continuous Loss Position, Total
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	9
Fair value available-for-sale securities	$ 116,631
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 2,115
CMBS
Continuous Loss Position Less Than Twelve Months
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year | security	30
Fair value available-for-sale securities	$ 195,913
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	$ 4,640
Continuous Unrealized Loss Position, Twelve Months Or Greater
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year | security	0
Fair value available-for-sale securities	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 0
Continuous Loss Position, Total
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	30
Fair value available-for-sale securities	$ 195,913
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 4,640
Other ABS
Continuous Loss Position Less Than Twelve Months
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year | security	28	34
Fair value available-for-sale securities	$ 114,059	$ 97,356
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	$ 273	$ 1,727
Continuous Unrealized Loss Position, Twelve Months Or Greater
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year | security	10	0
Fair value available-for-sale securities	$ 39,860	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 471	$ 0
Continuous Loss Position, Total
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	38	34
Fair value available-for-sale securities	$ 153,919	$ 97,356
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 744	$ 1,727
Foreign government securities
Continuous Loss Position Less Than Twelve Months
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Less than One Year | security	11	4
Fair value available-for-sale securities	$ 10,971	$ 6,353
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss	$ 340	$ 242
Continuous Unrealized Loss Position, Twelve Months Or Greater
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions, Greater than or Equal to One Year | security	1	0
Fair value available-for-sale securities	$ 183	$ 0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	$ 16	$ 0
Continuous Loss Position, Total
Available-for-sale, Securities in Unrealized Loss Positions, Qualitative Disclosure, Number of Positions | security	12	4
Fair value available-for-sale securities	$ 11,154	$ 6,353
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	$ 356	$ 242