Summary of Significant Accounting Policies (Impact of Adoption of New Accounting Standard Related to CECL) (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Jan. 01, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020	$ 158	$ 160
Financing Receivable, Allowance for Credit Loss	248,666	263,177
Off-Balance Sheet, Credit Loss, Liability	50,314	44,152		$ 500		$ 500
Cumulative effect of accounting change				(29,252)		(14,672)
Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			$ (29,300)	(29,252)	$ (14,700)	(14,672)
Commercial Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	72,091	73,843		51,593		48,580
Commercial Portfolio Segment [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			(16,798)
Commercial and Industrial Total Energy Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	17,217	39,553		37,382		29,052
Commercial and Industrial Total Energy Loans [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			8,258
Commercial Real Estate Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	144,936	134,892		31,037		38,777
Commercial Real Estate Portfolio Segment [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			10,680
Total consumer real estate loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	6,585	7,926		4,113		6,103
Total consumer real estate loans [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			(1,890)
Consumer Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	7,837	6,963		8,042		9,620
Consumer Loan [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			1,776
Loans Receivable [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss	248,666	263,177		132,167		$ 132,132
Loans Receivable [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			2,026
US Treasury [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			0
Residential Mortgage Backed Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020	0	0
Residential Mortgage Backed Securities [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			0
States and Political Subdivisions [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020	158	160
States and Political Subdivisions [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			(170)
Other [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020	0	0
Other [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			0
Debt Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020	158	$ 160		$ 0
Debt Securities [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			(170)
Commitments to Extend Credit [Member] | Retained Earnings [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Cumulative effect of accounting change			(31,108)
Pre-Adoption Allowance [Member] | Commercial Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			51,593
Pre-Adoption Allowance [Member] | Commercial and Industrial Total Energy Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			37,382
Pre-Adoption Allowance [Member] | Commercial Real Estate Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			31,037
Pre-Adoption Allowance [Member] | Total consumer real estate loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			4,113
Pre-Adoption Allowance [Member] | Consumer Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			8,042
Pre-Adoption Allowance [Member] | Loans Receivable [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			132,167
Pre-Adoption Allowance [Member] | US Treasury [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			0
Pre-Adoption Allowance [Member] | Residential Mortgage Backed Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			0
Pre-Adoption Allowance [Member] | States and Political Subdivisions [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			0
Pre-Adoption Allowance [Member] | Other [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			0
Pre-Adoption Allowance [Member] | Debt Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			0
Pre-Adoption Allowance [Member] | Commitments to Extend Credit [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Off-Balance Sheet, Credit Loss, Liability			500
Accounting Standards Update 2016-13 [Member] | Commercial Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			21,263
Accounting Standards Update 2016-13 [Member] | Commercial and Industrial Total Energy Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			(10,453)
Accounting Standards Update 2016-13 [Member] | Commercial Real Estate Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			(13,519)
Accounting Standards Update 2016-13 [Member] | Total consumer real estate loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			2,392
Accounting Standards Update 2016-13 [Member] | Consumer Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			(2,248)
Accounting Standards Update 2016-13 [Member] | Loans Receivable [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			(2,565)
Accounting Standards Update 2016-13 [Member] | US Treasury [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			0
Accounting Standards Update 2016-13 [Member] | Residential Mortgage Backed Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			0
Accounting Standards Update 2016-13 [Member] | States and Political Subdivisions [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			215
Accounting Standards Update 2016-13 [Member] | Other [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			0
Accounting Standards Update 2016-13 [Member] | Debt Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020	$ 0		215
Accounting Standards Update 2016-13 [Member] | Commitments to Extend Credit [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Off-Balance Sheet, Credit Loss, Liability			39,377
Post-Adoption Allowance [Member] | Commercial Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			72,856
Post-Adoption Allowance [Member] | Commercial and Industrial Total Energy Loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			26,929
Post-Adoption Allowance [Member] | Commercial Real Estate Portfolio Segment [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			17,518
Post-Adoption Allowance [Member] | Total consumer real estate loans [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			6,505
Post-Adoption Allowance [Member] | Consumer Loan [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			5,794
Post-Adoption Allowance [Member] | Loans Receivable [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Financing Receivable, Allowance for Credit Loss			129,602
Post-Adoption Allowance [Member] | US Treasury [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			0
Post-Adoption Allowance [Member] | Residential Mortgage Backed Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			0
Post-Adoption Allowance [Member] | States and Political Subdivisions [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			215
Post-Adoption Allowance [Member] | Other [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			0
Post-Adoption Allowance [Member] | Debt Securities [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Securities held to maturity, net of allowance for credit losses of $158 in 2021 and $160 in 2020			215
Post-Adoption Allowance [Member] | Commitments to Extend Credit [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Off-Balance Sheet, Credit Loss, Liability			$ 39,877