Regulatory Matters (Details) $ / shares in Units, $ in Thousands	6 Months Ended
	Jun. 30, 2017 USD ($) $ / shares
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Preceding period of retained earnings used in calculation of dividend payable	2 years
Quarterly common stock dividend (in dollar per share) | $ / shares	$ 0.14
Pinnacle Financial
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Cash dividends paid to Pinnacle Financial by Pinnacle Bank	$ 15,700
Actual
Total capital to risk weighted assets	2,180,808
Tier I capital to risk weighted assets	1,645,173
Common Equity Tier I capital to risk weighted assets	1,645,051
Tier I capital to average assets	$ 1,645,173	[1]
Actual
Total capital to risk weighted assets (as percent)	12.60%
Tier I capital to risk weighted assets (as percent)	9.50%
Common Equity Tier I capital to risk weighted assets (as percent)	9.50%
Tier I capital to average assets (as percent)	14.50%	[1]
Minimum Capital Requirement
Total capital to risk weighted assets	$ 1,382,821
Tier I capital to risk weighted assets	1,037,116
Common Equity Tier I capital	777,837
Tier I capital to average assets	$ 454,114	[1]
Minimum Capital Requirement
Total capital to risk weighted assets (as percent)	8.00%
Tier I capital to risk weighted assets (as percent)	6.00%
Common Equity Tier I capital to risk weighted assets (as percent)	4.50%
Tier I capital to average assets (as percent)	4.00%	[1]
Pinnacle Bank
Actual
Total capital to risk weighted assets	$ 2,081,349
Tier I capital to risk weighted assets	1,888,732
Common Equity Tier I capital to risk weighted assets	1,888,610
Tier I capital to average assets	$ 1,888,732	[1]
Actual
Total capital to risk weighted assets (as percent)	12.10%
Tier I capital to risk weighted assets (as percent)	11.00%
Common Equity Tier I capital to risk weighted assets (as percent)	11.00%
Tier I capital to average assets (as percent)	16.70%	[1]
Minimum Capital Requirement
Total capital to risk weighted assets	$ 1,378,433
Tier I capital to risk weighted assets	1,033,825
Common Equity Tier I capital	775,368
Tier I capital to average assets	$ 453,095	[1]
Minimum Capital Requirement
Total capital to risk weighted assets (as percent)	8.00%
Tier I capital to risk weighted assets (as percent)	6.00%
Common Equity Tier I capital to risk weighted assets (as percent)	4.50%
Tier I capital to average assets (as percent)	4.00%	[1]
Minimum To Be Well-Capitalized
Total capital to risk weighted assets	$ 1,723,041
Tier I capital to risk weighted assets	1,378,433
Common Equity Tier I capital to risk weighted assets	1,119,977
Tier I capital to average assets	$ 566,368	[1]
Minimum To Be Well-Capitalized
Total capital to risk weighted assets (as percent)	10.00%
Tier I capital to risk weighted assets (as percent)	8.00%
Common Equity Tier I capital to risk weighted assets (as percent)	6.50%
Tier I capital to average assets (as percent)	5.00%	[1]

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