CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total		BNC Bancorp	Common Stock	Common Stock BNC Bancorp	Additional Paid-in Capital	Additional Paid-in Capital BNC Bancorp	Retained Earnings	AOCI Attributable to Parent
Balance (in shares) at Dec. 31, 2016				46,359,000
Balance at Dec. 31, 2016	$ 1,496,696			$ 46,359		$ 1,083,491		$ 381,072	$ (14,226)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of employee common stock options, stock appreciation rights, and related tax benefits (in shares)	275,904	[1]		276,000
Exercise of employee common stock options, stock appreciation rights, and related tax benefits	$ 5,485			$ 276		5,209
Common dividends paid	35,907							35,907
Issuance of restricted common shares, net of forfeitures (in shares)				272,000
Issuance of restricted common shares, net of forfeitures	0			$ 272		(272)
Issuance of common stock (in shares)				3,220,000
Issuance of common stock	192,194			$ 3,220		188,974
Common stock issued in conjunction with acquisition (in shares)					27,687,000
Common stock issued in conjunction with acquisition	1,850,968		$ 1,850,968		$ 27,687		$ 1,823,281
Restricted shares withheld for taxes (in shares)				(74,000)
Restricted shares withheld for taxes	(4,991)			$ (74)		(4,917)
Restricted stock expense	19,538
Net income	173,979							173,979
Other Comprehensive Income (Loss)	9,990								9,990
Balance (in shares) at Dec. 31, 2017				77,740,000
Balance at Dec. 31, 2017	$ 3,707,952			$ 77,740		3,115,304		519,144	(4,236)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
APIC, Share-based Payment Arrangement, Increase for Cost Recognition						19,538
Exercise of employee common stock options, stock appreciation rights, and related tax benefits (in shares)	97,877			98,000
Exercise of employee common stock options, stock appreciation rights, and related tax benefits	$ 1,851			$ 98		1,753
Repurchase of common stock (in shares)				(405,000)
Repurchase of common stock	(20,694)			$ (405)		(20,289)
Common dividends paid	45,454							45,454
Issuance of restricted common shares, net of forfeitures (in shares)				157,000
Issuance of restricted common shares, net of forfeitures	0			$ 157		(157)
Common stock issued in conjunction with acquisition	0
Restricted shares withheld for taxes (in shares)				(106,000)
Restricted shares withheld for taxes	(6,922)			$ (106)		(6,816)
Restricted stock expense	17,636
Net income	359,440							359,440
Other Comprehensive Income (Loss)	(47,869)								(47,869)
Balance (in shares) at Dec. 31, 2018				77,484,000
Balance at Dec. 31, 2018	$ 3,965,940			$ 77,484		3,107,431		833,130	(52,105)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
APIC, Share-based Payment Arrangement, Increase for Cost Recognition						17,636
Exercise of employee common stock options, stock appreciation rights, and related tax benefits (in shares)	59,317			59,000
Exercise of employee common stock options, stock appreciation rights, and related tax benefits	$ 1,269			$ 59		1,210
Repurchase of common stock (in shares)				(1,102,000)
Repurchase of common stock	(61,416)			$ (1,102)		(60,314)
Common dividends paid	49,828							49,828
Issuance of restricted common shares, net of forfeitures (in shares)				211,000
Issuance of restricted common shares, net of forfeitures	0			$ 211		(211)
Common stock issued in conjunction with acquisition	0
Restricted shares withheld for taxes (in shares)				(88,000)
Restricted shares withheld for taxes	(4,963)			$ (88)		(4,875)
Restricted stock expense	21,226
Net income	400,881							400,881
Other Comprehensive Income (Loss)	82,639								82,639
Balance (in shares) at Dec. 31, 2019				76,564,000
Balance at Dec. 31, 2019	$ 4,355,748			$ 76,564		3,064,467		$ 1,184,183	$ 30,534
Increase (Decrease) in Stockholders' Equity [Roll Forward]
APIC, Share-based Payment Arrangement, Increase for Cost Recognition						$ 21,226

[1] Includes 750 stock options which were exercised in a stock swap transaction which settled in 277 shares of Pinnacle Financial common stock.