Note 10 - Earnings Per Share - Computation of Basic and Diluted Earnings per Share (Details) $ / shares in Units, $ in Thousands		3 Months Ended					6 Months Ended
	Jun. 30, 2023 USD ($) $ / shares shares	Jun. 30, 2023 USD ($) $ / shares shares	Jun. 20, 2023 USD ($) $ / shares shares	Mar. 31, 2023 USD ($)	Jun. 30, 2022 USD ($) $ / shares shares	Mar. 31, 2022 USD ($)	Jun. 30, 2023 USD ($) $ / shares shares	Jun. 20, 2023 USD ($) $ / shares shares	Jun. 30, 2022 USD ($) $ / shares shares
EARNINGS PER SHARE
Net income | $		$ 7,556	$ 6,125	$ 25,257	$ 33,280	$ 41,471	$ 32,813	$ 31,382	$ 74,751
Weighted average shares used to compute basic EPS (in shares)			44,414,000		44,271,000			44,344,000	44,226,000
Weighted average shares used to compute diluted EPS (in shares)			44,819,000		45,135,000			44,752,000	45,022,000
Basic (in dollars per share) | $ / shares		$ 0.17	$ 0.14		$ 0.75		$ 0.74	$ 0.71	$ 1.69
Diluted (in dollars per share) | $ / shares		$ 0.17	$ 0.14		$ 0.74		$ 0.73	$ 0.70	$ 1.66
Ratio of participation in earnings for common stock and preferred stock								1
Cash dividends declared | $		$ 5,734			$ 4,998	$ 2,497
Restricted Stock Units
EARNINGS PER SHARE
Antidilutive shares								684,151
Performance Stock Units
EARNINGS PER SHARE
Antidilutive shares								248,706
Employee Stock Option [Member]
EARNINGS PER SHARE
Dilutive effect of stock-based awards (in shares)			350,000		615,000			381,000	610,000
Restricted Stock Units
EARNINGS PER SHARE
Dilutive effect of stock-based awards (in shares)					249,000				186,000
Performance Stock Units
EARNINGS PER SHARE
Dilutive effect of stock-based awards (in shares)			55,000					27,000
Class A Common Stock
EARNINGS PER SHARE
Net income | $	$ 1,326
Weighted average shares used to compute basic EPS (in shares)	41,123,000
Weighted average shares used to compute diluted EPS (in shares)	41,712,000
Basic (in dollars per share) | $ / shares	$ 0.03
Diluted (in dollars per share) | $ / shares	$ 0.03
Class A Common Stock | Restricted Stock Units
EARNINGS PER SHARE
Antidilutive shares	165,803
Class A Common Stock | Performance Stock Units
EARNINGS PER SHARE
Antidilutive shares	248,706
Class A Common Stock | Employee Stock Option [Member]
EARNINGS PER SHARE
Dilutive effect of stock-based awards (in shares)	326,000
Class A Common Stock | Restricted Stock
EARNINGS PER SHARE
Unvested restricted stock	3,239,000	3,239,000					3,239,000
Class A Common Stock | Restricted Stock Units
EARNINGS PER SHARE
Dilutive effect of stock-based awards (in shares)	39,000
Class A Common Stock | Performance Stock Units
EARNINGS PER SHARE
Dilutive effect of stock-based awards (in shares)	224,000
Class B Common Stock
EARNINGS PER SHARE
Weighted average shares used to compute basic EPS (in shares)	8,225,000
Weighted average shares used to compute diluted EPS (in shares)	8,432,000
Cash dividends declared | $		$ 0
Class B Common Stock | Performance Stock Units
EARNINGS PER SHARE
Antidilutive shares	49,737
Class B Common Stock | Employee Stock Option [Member]
EARNINGS PER SHARE
Dilutive effect of stock-based awards (in shares)	93,000
Class B Common Stock | Restricted Stock
EARNINGS PER SHARE
Unvested restricted stock	648,000	648,000					648,000
Class B Common Stock | Restricted Stock Units
EARNINGS PER SHARE
Dilutive effect of stock-based awards (in shares)	32,000
Class B Common Stock | Performance Stock Units
EARNINGS PER SHARE
Dilutive effect of stock-based awards (in shares)	82,000
Class A Restricted Stock
EARNINGS PER SHARE
Net income | $	$ 105