Note 1 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2021

Notes Tables

Schedule of Estimated Useful Lives of Assets [Table Text Block]

Type	Estimated Useful Life (years)
Buildings	15	to	45
Building improvements	5	to	20
Furniture, fixtures, and equipment	3	to	25
Leasehold improvements	Shorter of useful lives or the terms of the leases

Accounting Standards Update and Change in Accounting Principle [Table Text Block]

	Balance at		Adjustments due to			Balance at
	December 31, 2020		Adoption of ASC 326			January 1, 2021
Assets:	(In thousands)
Allowance for credit losses on loans	$	166,538	$	(1,560	)	$	164,978
Deferred tax assets		85,610		1,319			86,929
Liabilities:
Allowance for unfunded commitments	$	5,880	$	6,018		$	11,898
Stockholders' equity:
Retained earnings, net of tax	$	2,418,144	$	(3,139	)	$	2,415,005