Regulatory Matters (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Regulatory Matters [Abstract]
Undivided profits		$ 110,600
Tier 1 capital to average assets [Abstract]
Capital conservation buffer		0.0250	0.0250
Components of regulatory capital [Abstract]
Total shareholders' equity		$ 355,449	$ 398,484	$ 387,329	$ 389,522
Add (deduct) [Abstract]
Accumulated other comprehensive income for regulatory purposes		(54,414)	501
Subordinated debt		$ 39,376	39,357
Period of transition method for regulatory purposes		3 years
Consolidated [Member]
Total capital to risk-weighted assets [Abstract]
Total risk-based capital	[1]	$ 499,363	$ 488,495
Actual, Ratio	[1]	0.1418	0.1453
Minimum for Adequately Capitalized Institutions, Amount	[1]	$ 281,788	$ 268,991
Minimum for Adequately Capitalized Institutions, Ratio	[1]	0.0800	0.0800
Tier 1 capital to risk-weighted assets [Abstract]
Actual, Amount	[1]	$ 416,199	$ 406,645
Actual, Ratio	[1]	0.1182	0.1209
Minimum for Adequately Capitalized Institutions, Amount	[1]	$ 211,341	$ 201,743
Minimum for Adequately Capitalized Institutions, Ratio	[1]	0.0600	0.0600
Common equity tier 1 capital to risk-weighted assets [Abstract]
Actual, Amount	[1]	$ 377,814	$ 368,277
Actual, Ratio	[1]	0.1073	0.1095
Minimum for Adequately Capitalized Institutions, Amount	[1]	$ 158,506	$ 151,307
Minimum for Adequately Capitalized Institutions, Ratio	[1]	0.0450	0.0450
Tier 1 capital to average assets [Abstract]
Tier 1 capital	[1]	$ 416,199	$ 406,645
Actual, Ratio	[1]	0.0881	0.0879
Minimum for Adequately Capitalized Institutions, Amount	[1]	$ 188,867	$ 185,034
Minimum for Adequately Capitalized Institutions, Ratio	[1]	0.0400	0.0400
Components of regulatory capital [Abstract]
Total shareholders' equity		$ 355,449	$ 398,484
Add (deduct) [Abstract]
Accumulated other comprehensive income for regulatory purposes		48,617	(6,298)
Goodwill and other intangibles		(31,404)	(31,636)
CECL	[2]	5,152	7,727
Common equity tier 1 capital	[1]	377,814	368,277
Qualifying trust preferred securities		38,385	38,368
Tier 1 capital	[1]	416,199	406,645
Subordinated debt		40,000	40,000
Allowance for credit losses and allowance for unfunded lending commitments limited to 1.25% of total risk-weighted assets		43,164	41,850
Total risk-based capital	[1]	499,363	488,495
Independent Bank [Member]
Total capital to risk-weighted assets [Abstract]
Total risk-based capital	[1]	$ 447,698	$ 438,352
Actual, Ratio	[1]	0.1271	0.1305
Minimum for Adequately Capitalized Institutions, Amount	[1]	$ 281,707	$ 268,808
Minimum for Adequately Capitalized Institutions, Ratio	[1]	0.0800	0.0800
Minimum for Well-Capitalized Institutions, Amount	[1]	$ 352,133	$ 336,011
Minimum for Well-Capitalized Institutions, Ratio	[1]	0.1000	0.1000
Tier 1 capital to risk-weighted assets [Abstract]
Actual, Amount	[1]	$ 404,534	$ 396,351
Actual, Ratio	[1]	0.1149	0.1180
Minimum for Adequately Capitalized Institutions, Amount	[1]	$ 211,280	$ 201,606
Minimum for Adequately Capitalized Institutions, Ratio	[1]	0.0600	0.0600
Minimum for Well-Capitalized Institutions, Amount	[1]	$ 281,707	$ 268,808
Minimum for Well-Capitalized Institutions, Ratio	[1]	0.0800	0.0800
Common equity tier 1 capital to risk-weighted assets [Abstract]
Actual, Amount	[1]	$ 404,534	$ 396,351
Actual, Ratio	[1]	0.1149	0.1180
Minimum for Adequately Capitalized Institutions, Amount	[1]	$ 158,460	$ 151,205
Minimum for Adequately Capitalized Institutions, Ratio	[1]	0.0450	0.0450
Minimum for Well-Capitalized Institutions, Amount	[1]	$ 228,887	$ 218,407
Minimum for Well-Capitalized Institutions, Ratio	[1]	0.0650	0.0650
Tier 1 capital to average assets [Abstract]
Tier 1 capital	[1]	$ 404,534	$ 396,351
Actual, Ratio	[1]	0.0856	0.0857
Minimum for Adequately Capitalized Institutions, Amount	[1]	$ 188,953	$ 185,077
Minimum for Adequately Capitalized Institutions, Ratio	[1]	0.0400	0.0400
Minimum for Well-Capitalized Institutions, Amount	[1]	$ 236,191	$ 231,347
Minimum for Well-Capitalized Institutions, Ratio	[1]	0.0500	0.0500
Components of regulatory capital [Abstract]
Total shareholders' equity		$ 382,169	$ 426,558
Add (deduct) [Abstract]
Accumulated other comprehensive income for regulatory purposes		48,617	(6,298)
Goodwill and other intangibles		(31,404)	(31,636)
CECL	[2]	5,152	7,727
Common equity tier 1 capital	[1]	404,534	396,351
Qualifying trust preferred securities		0	0
Tier 1 capital	[1]	404,534	396,351
Subordinated debt		0	0
Allowance for credit losses and allowance for unfunded lending commitments limited to 1.25% of total risk-weighted assets		43,164	42,001
Total risk-based capital	[1]	$ 447,698	$ 438,352

[1] These ratios do not reflect a capital conservation buffer of 2.50% at March 31, 2022 and December 31, 2021.

[2] We elected the three year CECL transition method for regulatory purposes.