Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Accounting Policies [Abstract]

Additional Cash Flow Information

Additional cash flow information was as follows:

	Year Ended December 31,
	2020		2019		2018
Cash paid for interest	$	49,300	$	124,781	$	89,270
Cash paid for income tax	44,140		45,352		5,112
Significant non-cash transactions:
Transfer of securities from available for sale to held to maturity	—		377,812		—
Unsettled securities transactions	57,783		—		330
Loans foreclosed and transferred to other real estate owned and foreclosed assets	140		1,348		2,899
Loans to facilitate the sale of other real estate owned	—		847		—
Right-of-use lease assets obtained in exchange for lessee operating lease liabilities	18,284		319,286		—
Treasury stock issued to 401(k) stock purchase plan	10,307		—		—

Accounting Standards Update and Change in Accounting Principle

The following table details the impact of the adoption of ASC 326 on the allowance for credit losses as of January 1, 2020.

	January 1, 2020
	Pre-Adoption Allowance		Impact of Adoption		Post-Adoption Allowance		Cumulative Effect on Retained Earnings
Securities held to maturity:
U.S. Treasury	$	—	$	—	$	—	$	—
Residential mortgage-backed securities	—		—		—		—
States and political subdivisions	—		215		215		(170)
Other	—		—		—		—
Total	$	—	$	215	$	215	$	(170)
Loans:
Commercial and industrial	$	51,593	$	21,263	$	72,856	$	(16,798)
Energy	37,382		(10,453)		26,929		8,258
Commercial real estate	31,037		(13,519)		17,518		10,680
Consumer real estate	4,113		2,392		6,505		(1,890)
Consumer and other	8,042		(2,248)		5,794		1,776
Total	$	132,167	$	(2,565)	$	129,602	$	2,026
Off-balance-sheet credit exposures	$	500	$	39,377	$	39,877	$	(31,108)