Regulatory Matters (Details) $ / shares in Units, shares in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2023 USD ($) $ / shares	Jun. 30, 2020 shares	Sep. 30, 2023 USD ($) $ / shares	Dec. 31, 2022 USD ($)		Dec. 31, 2021 $ / shares
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Preceding period of retained earnings used in calculation of dividend payable				2 years
Retained earnings		$ 2,745,934,000		$ 2,745,934,000	$ 2,341,706,000
Quarterly common stock dividend (in dollar per share) | $ / shares		$ 0.22		$ 0.22			$ 0.18
Depositary Shares | shares			9,000
Preferred Stock, Dividend Rate, Per-Dollar-Amount | $ / shares		$ 16.88
Preferred Stock, Dividend Per Depositary Share		$ 0.422
Pinnacle Financial
Actual
Total capital to risk weighted assets		5,060,635,000		$ 5,060,635,000	4,584,292,000
Tier I capital to risk weighted assets		4,302,258,000		4,302,258,000	3,888,100,000
Common equity Tier 1 capital to risk weighted assets		4,085,010,000		4,085,010,000	3,670,851,000
Tier I capital to average assets	[1]	$ 4,302,258,000		$ 4,302,258,000	$ 3,888,100,000
Actual
Total capital to risk weighted assets (as percent)		0.128		0.128	0.124
Tier I capital to risk weighted assets (as percent)		0.109		0.109	0.105
Common equity Tier 1 capital to risk weighted assets		0.103		0.103	0.100
Tier I capital to average assets (as percent)	[1]	0.094		0.094	0.097
Minimum Capital Requirement
Total capital to risk weighted assets		$ 3,162,167,000		$ 3,162,167,000	$ 2,949,276,000
Tier I capital to risk weighted assets		2,371,625,000		2,371,625,000	2,211,957,000
Common equity Tier 1 capital to risk weighted assets		1,778,719,000		1,778,719,000	1,658,968,000
Tier I capital to average assets	[1]	$ 1,830,252,000		$ 1,830,252,000	$ 1,595,457,000
Minimum Capital Requirement
Total capital to risk weighted assets (as percent)		0.080		0.080	0.080
Tier I capital to risk weighted assets (as percent)		0.060		0.060	0.060
Common Equity Tier I capital to risk weighted assets (as percent)		0.045		0.045	0.045
Tier I capital to average assets (as percent)	[1]	0.040		0.040	0.040
Minimum To Be Well-Capitalized (1)
Total capital to risk weighted assets		$ 3,952,709,000		$ 3,952,709,000	$ 3,686,595,000	[2]
Tier I capital to risk weighted assets	[2]	$ 2,371,625,000		$ 2,371,625,000	$ 2,211,957,000
Minimum To Be Well-Capitalized (1)
Total capital to risk weighted assets (as percent)		0.100		0.100	0.100	[2]
Tier I capital to risk weighted assets (as percent)	[2]	0.060		0.060	0.060
Pinnacle Bank
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash dividends paid to Pinnacle Financial by Pinnacle Bank				$ 79,500,000
Retained earnings		$ 1,300,000,000		1,300,000,000
Actual
Total capital to risk weighted assets		4,746,496,000		4,746,496,000	$ 4,282,742,000
Tier I capital to risk weighted assets		4,417,120,000		4,417,120,000	4,015,550,000
Common equity Tier 1 capital to risk weighted assets		4,416,997,000		4,416,997,000	4,015,427,000
Tier I capital to average assets	[1]	$ 4,417,120,000		$ 4,417,120,000	$ 4,015,550,000
Actual
Total capital to risk weighted assets (as percent)		0.120		0.120	0.116
Tier I capital to risk weighted assets (as percent)		0.112		0.112	0.109
Common equity Tier 1 capital to risk weighted assets		0.112		0.112	0.109
Tier I capital to average assets (as percent)	[1]	0.097		0.097	0.101
Minimum Capital Requirement
Total capital to risk weighted assets		$ 3,152,420,000		$ 3,152,420,000	$ 2,941,082,000
Tier I capital to risk weighted assets		2,364,315,000		2,364,315,000	2,205,812,000
Common equity Tier 1 capital to risk weighted assets		1,773,236,000		1,773,236,000	1,654,359,000
Tier I capital to average assets	[1]	$ 1,827,027,000		$ 1,827,027,000	$ 1,591,502,000
Minimum Capital Requirement
Total capital to risk weighted assets (as percent)		0.080		0.080	0.080
Tier I capital to risk weighted assets (as percent)		0.060		0.060	0.060
Common Equity Tier I capital to risk weighted assets (as percent)		0.045		0.045	0.045
Tier I capital to average assets (as percent)	[1]	0.040		0.040	0.040
Minimum To Be Well-Capitalized (1)
Total capital to risk weighted assets		$ 3,940,525,000		$ 3,940,525,000	$ 3,676,353,000	[2]
Tier I capital to risk weighted assets	[2]	3,152,420,000		3,152,420,000	2,941,082,000
Common equity Tier 1 capital to risk weighted assets	[2]	2,561,341,000		2,561,341,000	2,389,629,000
Tier I capital to average assets	[1],[2]	$ 2,283,783,000		$ 2,283,783,000	$ 1,989,378,000
Minimum To Be Well-Capitalized (1)
Total capital to risk weighted assets (as percent)		0.100		0.100	0.100	[2]
Tier I capital to risk weighted assets (as percent)	[2]	0.080		0.080	0.080
Common Equity Tier I capital to risk weighted assets (as percent)	[2]	0.065		0.065	0.065
Tier I capital to average assets (as percent)	[1],[2]	0.050		0.050	0.050

[1] (*) Average assets for the above calculations were based on the most recent quarter.

[2] Well-capitalized minimum Common equity Tier 1 capital to risk weighted assets and Tier 1 capital to average assets are not formally defined under applicable banking regulations for bank holding companies.