Fair Value of Financial Instruments - Carrying Amount and Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		Jun. 30, 2022		Dec. 31, 2021
Financial assets:
Securities purchased with agreement to resell		$ 1,328,876		$ 1,000,000
Securities held-to-maturity		2,484,358		1,188,049
Quoted market prices in an active market (Level 1)
Financial assets:
Securities purchased with agreement to resell		0		0
Securities held-to-maturity		0		0
Loans, net		0		0
Consumer loans held-for-sale		0		0
Commercial loans held-for-sale		0		0
Financial liabilities:
Deposits and securities sold under agreements to repurchase		0		0
Federal Home Loan Bank advances		0		0
Subordinated debt and other borrowings		0		0
Off-balance sheet instruments:
Commitments to extend credit	[1]	0		0
Models with significant observable market parameters (Level 2)
Financial assets:
Securities purchased with agreement to resell		0		0
Securities held-to-maturity		2,484,358		1,188,049
Loans, net		0		0
Consumer loans held-for-sale		67,477		46,288
Commercial loans held-for-sale		25,905		17,871
Financial liabilities:
Deposits and securities sold under agreements to repurchase		0		0
Federal Home Loan Bank advances		0		0
Subordinated debt and other borrowings		0		0
Off-balance sheet instruments:
Commitments to extend credit	[1]	0		0
Models with significant unobservable market parameters (Level 3)
Financial assets:
Securities purchased with agreement to resell		1,267,352		980,543
Securities held-to-maturity		0		0
Loans, net		25,535,858		23,223,299
Consumer loans held-for-sale		0		0
Commercial loans held-for-sale		0		0
Financial liabilities:
Deposits and securities sold under agreements to repurchase		31,729,054		30,812,222
Federal Home Loan Bank advances		1,476,589		1,006,866
Subordinated debt and other borrowings		445,745		479,879
Off-balance sheet instruments:
Commitments to extend credit	[1]	25,821		24,351
Carrying/ Notional Amount
Financial assets:
Securities purchased with agreement to resell		1,328,876		1,000,000
Securities held-to-maturity		2,744,555		1,155,958
Loans, net		26,060,613		23,151,029
Consumer loans held-for-sale		67,467		45,806
Commercial loans held-for-sale		25,901		17,685
Financial liabilities:
Deposits and securities sold under agreements to repurchase		32,794,888		31,457,092
Federal Home Loan Bank advances		1,289,059		888,681
Subordinated debt and other borrowings		423,614		423,172
Off-balance sheet instruments:
Commitments to extend credit	[1]	14,772,651		13,063,942
Estimated Fair Value
Financial assets:
Securities purchased with agreement to resell		1,267,352	[2]	980,543
Securities held-to-maturity	[2]	2,484,358		1,188,049
Loans, net	[2]	25,535,858		23,223,299
Consumer loans held-for-sale	[2]	67,477		46,288
Commercial loans held-for-sale	[2]	25,905		17,871
Financial liabilities:
Deposits and securities sold under agreements to repurchase	[2]	31,729,054		30,812,222
Federal Home Loan Bank advances	[2]	1,476,589		1,006,866
Subordinated debt and other borrowings	[2]	445,745		479,879
Off-balance sheet instruments:
Commitments to extend credit	[1],[2]	$ 25,821		$ 24,351

[1] At the end of each quarter, Pinnacle Financial evaluates the inherent risks of the outstanding off-balance sheet commitments, including both commitments for unfunded loans and standby letters of credit. In making this evaluation, Pinnacle Financial utilizes credit loss expectations on funded loans from our allowance for credit losses methodology and evaluates the probability that the outstanding commitment will eventually become a funded loan. As a result, at June 30, 2022 and December 31, 2021, Pinnacle Financial included in other liabilities $24.0 million and $22.5 million, respectively, representing expected credit losses on off-balance sheet commitments, which are reflected in the estimated fair values of the related commitments. Also included in the fair values at June 30, 2022 and December 31, 2021 are unamortized fees related to these commitments of $1.9 million.

[2] Estimated fair values are consistent with an exit-price concept. The assumptions used to estimate the fair values are intended to approximate those that a market-participant would realize in a hypothetical orderly transaction.