Consolidated Statements of Changes in Shareholders' Equity - USD ($) $ in Thousands		Total	Common Stock	Additional Paid in Capital	Retained Earnings	Accumulated Other Comprehensive Income (Loss)
Beginning balance at Dec. 31, 2015		$ 1,015,974	$ 38,168	$ 725,280	$ 281,558	$ (29,032)
Changes in Stockholders' Equity
Comprehensive income		97,028			108,032	(11,004)
Cash dividends declared		(49,389)			(49,389)
Issuance of common stock and common stock equivalents in business combinations		1,504,811	32,074	1,472,737
Net shares issued under share-based compensation plans		(350)	351	(701)
Share-based compensation expense		13,452	6	13,446
Ending balance at Dec. 31, 2016		2,581,526	70,599	2,210,762	340,201	(40,036)
Changes in Stockholders' Equity
Cumulative effect adjustment of change in accounting policy, net of tax impact	[1]	3,659			3,659
Comprehensive income		168,579			149,523	19,056
Cash dividends declared		(78,498)			(78,498)
Net shares issued under share-based compensation plans		(23,863)	608	(24,471)
Share-based compensation expense		17,346	0	17,346
Reclassification of certain income tax effects	[2]	0			4,518	(4,518)
Ending balance at Dec. 31, 2017		2,668,749	71,207	2,203,637	419,403	(25,498)
Changes in Stockholders' Equity
Cumulative effect adjustment of change in accounting policy, net of tax impact	[1]	1,339			1,680	(341)
Comprehensive income		248,749			284,020	(35,271)
Cash dividends declared		(88,954)			(88,954)
Net shares issued under share-based compensation plans		(2,201)	253	(2,454)
Share-based compensation expense		8,578	0	8,578
Ending balance at Dec. 31, 2018		$ 2,836,260	$ 71,460	$ 2,209,761	$ 616,149	$ (61,110)

[1] Refer to Note 1, Summary of Significant Accounting Policies, Note 4, Investment Securities, Note 7, Other Real Estate Owned and Repossessed Assets and Note 9, Loan Servicing Rights, for further details on the changes in accounting policy.

[2] The reclassification from accumulated other comprehensive income (loss) to retained earnings was due to the early adoption of ASU 2018-02, refer to Note 1 for further details on the adoption.