Consolidated Statement of Changes in Shareholders' Equity (Unaudited) - USD ($) $ in Thousands	Preferred Stock Series H	Non-Voting Common Stock	Common Stock	Common Stock Issuable	Capital Surplus	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Dec. 31, 2014		$ 10,081	$ 50,178	$ 5,168	$ 1,080,508	$ (387,568)	$ (18,790)	$ 739,577
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						53,370		53,370
Other comprehensive income							3,662	3,662
Common stock issued to dividend reinvestment plan and to employee benefit plans (11,761 and 15,844 shares for September 30, 2015 and September 30, 2016 respectively)			12		192			204
Conversion of non-voting common stock to voting (1,795,271 and 5,285,516 shares for September 30, 2015 and September 30, 2016 respectively)		(1,795)	1,795
Common and preferred stock issued for acquisition (11,058,515 common shares and 9,992 preferred shares)	$ 9,992		11,059		203,092			224,143
Amortization of stock option and restricted stock awards					3,343			3,343
Vesting of restricted stock, net of shares surrendered to cover payroll taxes (118,672 shares issued, 106,935 shares deferred and 79,430 shares issued, 94,497 shares deferred for September 30, 2015 and September 30, 2016)			119	1,444	(3,009)			(1,446)
Deferred compensation plan, net, including dividend equivalents				274	(1)			273
Shares issued from deferred compensation plan (23,613 and 45,758 shares for September 30, 2015 and September 30, 2016 respectively)			23	(216)	193
Common stock dividends ($.16 and $.22 per share for September 30, 2015 and September 30, 2016)						(10,506)		(10,506)
Tax on restricted stock vesting					559			559
Preferred stock dividends:
Series H						(42)		(42)
Balance at Sep. 30, 2015	9,992	8,286	63,186	6,670	1,284,877	(344,746)	(15,128)	1,013,137
Balance at Dec. 31, 2015	9,992	5,286	66,198	6,779	1,286,361	(330,879)	(25,452)	1,018,285
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income						73,435		73,435
Other comprehensive income							25,110	25,110
Redemption of Series H preferred stock (9,992 shares)	$ (9,992)							(9,992)
Common stock issued to dividend reinvestment plan and to employee benefit plans (11,761 and 15,844 shares for September 30, 2015 and September 30, 2016 respectively)			16		254			270
Conversion of non-voting common stock to voting (1,795,271 and 5,285,516 shares for September 30, 2015 and September 30, 2016 respectively)		$ (5,286)	5,286
Amortization of stock option and restricted stock awards					3,257			3,257
Vesting of restricted stock, net of shares surrendered to cover payroll taxes (118,672 shares issued, 106,935 shares deferred and 79,430 shares issued, 94,497 shares deferred for September 30, 2015 and September 30, 2016)			79	1,384	(2,428)			(965)
Purchases of common stock (764,000 shares)			(764)		(12,895)			(13,659)
Deferred compensation plan, net, including dividend equivalents				291				291
Shares issued from deferred compensation plan (23,613 and 45,758 shares for September 30, 2015 and September 30, 2016 respectively)			46	(1,275)	1,229
Common stock dividends ($.16 and $.22 per share for September 30, 2015 and September 30, 2016)						(15,849)		(15,849)
Tax on restricted stock vesting					(869)			(869)
Preferred stock dividends:
Series H						(21)		(21)
Balance at Sep. 30, 2016			$ 70,861	$ 7,179	$ 1,274,909	$ (273,314)	$ (342)	$ 1,079,293