CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Class A Common Shares Outstanding	Common Stock	Additional Paid-in Capital	Treasury Stock	Retained Earnings	Accumulated OCI
Balance at Dec. 31, 2018	$ 1,438,274		$ 836	$ 1,041,000	$ (22,010)	$ 461,360	$ (42,912)
Balance, Shares at Dec. 31, 2018		82,497
Net (loss) income	58,201					58,201
Equity-based compensation cost	1,188			1,188
Cash dividends declared	(22,727)					(22,727)
Dividend equivalents on restricted stock units	(125)					(125)
Purchase of treasury stock, at cost	(58,830)				(58,830)
Purchase of treasury stock, at cost, Shares		(3,002)
Issuance of common shares for State Bank acquisition	826,113		492	825,621
Issuance of common shares for State Bank acquisition, Shares		49,232
Value of stock warrants assumed from State Bank	251			251
Common stock issuance costs	(295)			(295)
Issuance of common shares for restricted stock unit vesting			1	(1)
Issuance of common shares for restricted stock unit vesting, Shares		35
Issuance of treasury stock shares for exercise of stock warrants				(7)	7
Other comprehensive income	60,773						60,773
Balance at Mar. 31, 2019	2,302,823		1,329	1,867,757	(80,833)	496,709	17,861
Balance, Shares at Mar. 31, 2019		128,762
Balance at Dec. 31, 2019	2,460,846		1,330	1,873,063	(100,752)	572,503	114,702
Balance, Shares at Dec. 31, 2019		127,598
Net (loss) income	(399,311)					(399,311)
Cumulative effect from adopting new accounting standard (Note 4)	(62,779)					(62,779)
Equity-based compensation cost	1,063			1,063
Cash dividends declared	(22,139)					(22,139)
Dividend equivalents on restricted stock units	(136)					(136)
Purchase of treasury stock, at cost	(29,973)				(29,973)
Purchase of treasury stock, at cost, Shares		(1,831)
Issuance of common shares for restricted stock unit vesting	1		1
Issuance of common shares for restricted stock unit vesting, Shares		131
Other comprehensive income	165,971						165,971
Balance at Mar. 31, 2020	$ 2,113,543		$ 1,331	$ 1,874,126	$ (130,725)	$ 88,138	$ 280,673
Balance, Shares at Mar. 31, 2020		125,898