Note 16 - Fair Value Disclosure of Financial Instruments - Assets and Liabilities Measured at Fair Value on a Recurring and Nonrecurring Basis (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Nonrecurring [Member]
Real estate	$ 24,899	$ 39,510
Other real estate investments	5,464	32,974
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 1 [Member]
Real estate	0	0
Other real estate investments	0	0
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 2 [Member]
Real estate	0	0
Other real estate investments	0	0
Fair Value, Nonrecurring [Member] | Fair Value, Inputs, Level 3 [Member]
Real estate	24,899	39,510
Other real estate investments	5,464	32,974
Fair Value, Recurring [Member]
Marketable equity securities	706,954	9,353
Marketable equity securities	706,954	9,353
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Marketable equity securities	706,954	9,353
Marketable equity securities	706,954	9,353
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Marketable equity securities	0
Marketable equity securities	$ 0
Fair Value, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Marketable equity securities		0
Marketable equity securities		$ 0