Note 6 - Debt and Equity Securities (Detail) - Securities available for sale by contractual maturity: (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Due in one year or less	$ 24,227
Due in one year or less	24,233
Due after one year through five years	59,018
Due after one year through five years	61,668
Due after five years through ten years	39,831
Due after five years through ten years	41,002
Due after ten years	105,590
Due after ten years	102,550
Total other securities	228,666
Total other securities	229,453	65,242
Mortgage-backed securities	687,281
Mortgage-backed securities	720,113	747,288
Total securities available for sale	915,947	791,730
Total securities available for sale	$ 949,566	$ 812,530