Regulatory Matters - Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations (Details)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
PEOPLES
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier one capital	$ 604,566,000	$ 577,565,000
Common equity tier one capital ratio	0.1192	0.1252
Common equity tier one capital required for capital adequacy	$ 228,206,000	$ 207,642,000
Common equity tier 1 risk based capital required for capital adequacy to risk weighted assets	4.50%	4.50%
Common equity tier one capital required to be well-capitalized	$ 329,631,000	$ 299,927,000
Common equity tier 1 risk based capital required to be well capitalized to risk weighted assets	6.50%	6.50%
Tier one risk based capital	$ 618,354,000	$ 591,215,000
Tier one risk based capital to risk weighted assets	0.1219	0.1281
Tier one risk based capital required for capital adequacy	$ 304,274,000	$ 276,856,000
Tier one risk based capital required for capital adequacy to risk weighted assets	0.0600	0.0600
Tier one risk based capital required to be well capitalized	$ 405,699,000	$ 369,141,000
Tier one risk based capital required to be well capitalized to risk weighted assets	0.0800	0.0800
Capital	$ 662,421,000	$ 648,948,000
Capital to risk ratio	0.1306	0.1406
Capital required for capital adequacy	$ 405,699,000	$ 369,141,000
Capital required for capital adequacy to risk ratio	0.0800	0.0800
Capital required to be well capitalized	$ 507,124,000	$ 461,426,000
Capital required to be well capitalized to risk ratio	0.1000	0.1000
Tier one leverage capital	$ 618,354,000	$ 591,215,000
Tier one leverage capital to ratio	0.0892	0.0867
Tier one leverage capital required for capital adequacy	$ 277,302,000	$ 272,916,000
Tier one leverage capital required for capital adequacy to average assets ratio	0.0400	0.0400
Tier one leverage capital required to be well capitalized	$ 346,628,000	$ 341,145,000
Tier one leverage capital required to be well capitalized to average assets ratio	0.0500	0.0500
Regulatory capital conservation buffer	$ 256,722,000	$ 279,807,000
Regulatory capital conservation buffer ratio	0.0506	0.0606
Risk weighted assets	5,071,240,000	4,614,259,000
PEOPLES BANK
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Common equity tier one capital	$ 593,609,000	$ 566,594,000
Common equity tier one capital ratio	0.1172	0.1230
Common equity tier one capital required for capital adequacy	$ 227,843,000	$ 207,318,000
Common equity tier 1 risk based capital required for capital adequacy to risk weighted assets	4.50%	4.50%
Common equity tier one capital required to be well-capitalized	$ 329,107,000	$ 299,460,000
Common equity tier 1 risk based capital required to be well capitalized to risk weighted assets	6.50%	6.50%
Tier one risk based capital	$ 593,609,000	$ 566,594,000
Tier one risk based capital to risk weighted assets	0.1172	0.1230
Tier one risk based capital required for capital adequacy	$ 303,791,000	$ 276,424,000
Tier one risk based capital required for capital adequacy to risk weighted assets	0.0600	0.0600
Tier one risk based capital required to be well capitalized	$ 405,055,000	$ 368,566,000
Tier one risk based capital required to be well capitalized to risk weighted assets	0.0800	0.0800
Capital	$ 637,676,000	$ 624,238,000
Capital to risk ratio	0.1259	0.1355
Capital required for capital adequacy	$ 405,055,000	$ 368,566,000
Capital required for capital adequacy to risk ratio	0.0800	0.0800
Capital required to be well capitalized	$ 506,318,000	$ 460,707,000
Capital required to be well capitalized to risk ratio	0.1000	0.1000
Tier one leverage capital	$ 593,609,000	$ 566,594,000
Tier one leverage capital to ratio	0.0858	0.0832
Tier one leverage capital required for capital adequacy	$ 276,712,000	$ 272,284,000
Tier one leverage capital required for capital adequacy to average assets ratio	0.0400	0.0400
Tier one leverage capital required to be well capitalized	$ 345,890,000	$ 340,355,000
Tier one leverage capital required to be well capitalized to average assets ratio	0.0500	0.0500
Regulatory capital conservation buffer	$ 232,621,000	$ 255,672,000
Regulatory capital conservation buffer ratio	0.0459	0.0555
Risk weighted assets	5,063,183,000	4,607,072,000
Minimum | PEOPLES
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Regulatory capital conservation buffer	126,781,000	115,356,000
Regulatory capital conservation buffer ratio	0.0250	0.0250
Minimum | PEOPLES BANK
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Regulatory capital conservation buffer	126,580,000	115,177,000
Regulatory capital conservation buffer ratio	$ 0.0250	$ 0.0250