Subsequent Events - Additional Information (Details)				1 Months Ended		2 Months Ended	12 Months Ended
	Jan. 22, 2019 $ / shares	Jan. 01, 2019 USD ($) $ / shares shares	Jul. 21, 2015 shares	Feb. 28, 2019 USD ($)	Nov. 30, 2016 shares	Feb. 28, 2019 USD ($) shares	Dec. 31, 2019 $ / shares	Dec. 31, 2018 USD ($) Bank $ / shares shares	Dec. 31, 2016 shares	Oct. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Subsequent Event [Line Items]
Cash dividends declared year to date, per common share | $ / shares								$ 0.55
Derivative, notional amount								$ 2,696,100,000			$ 2,350,759,000
Maximum
Subsequent Event [Line Items]
Share repurchase program authorized amount								$ 81,000,000		$ 50,000,000
Share repurchase program authorized number of shares | shares								4,300,000
Scenario Plan | Common Stock
Subsequent Event [Line Items]
Cash dividends declared year to date, per common share | $ / shares							$ 0.70
Restricted Stock Units
Subsequent Event [Line Items]
Restricted stock granted | shares			258,375		395,250			276,451	277,500
Perfomrnace goals duration, Minimum								3 years
Perfomrnace goals duration, Maximum								4 years
State Bank Financial Corporation
Subsequent Event [Line Items]
Acquisition costs related to transaction								$ 3,000,000
Business combination total assets reported								4,900,000,000
Business combination total loans reported								3,400,000,000
Business combination total deposits reported								$ 4,100,000
GEORGIA | State Bank Financial Corporation
Subsequent Event [Line Items]
Number of banking locations | Bank								32
Subsequent Event
Subsequent Event [Line Items]
Vesting period		3 years
Options granted | shares		1,600,000
Weighted average price, options | $ / shares		$ 20.43
Share repurchased, share | shares						1,800,000
Share repurchased, value						$ 34,500,000
Derivative, notional amount				$ 4,000,000,000		4,000,000,000
Derrivative contract term				5 years
Derivative, purchased option price				$ 127,800,000		$ 127,800,000
Subsequent Event | Purchased | Interest Rate Caps
Subsequent Event [Line Items]
Derrivative cap interest rate				4.70%		4.70%
Subsequent Event | Purchased | Interest Rate Floors
Subsequent Event [Line Items]
Derrivative floor interest rate				3.00%		3.00%
Subsequent Event | Sold | Interest Rate Caps
Subsequent Event [Line Items]
Derrivative cap interest rate				3.50%		3.50%
Subsequent Event | Sold | Interest Rate Floors
Subsequent Event [Line Items]
Derrivative floor interest rate				0.00%		0.00%
Subsequent Event | Common Stock
Subsequent Event [Line Items]
Cash dividends declared year to date, per common share | $ / shares	$ 0.175
Dividend paid date	Mar. 15, 2019
Dividend record date	Mar. 01, 2019
Dividend declared date	Jan. 22, 2019
Subsequent Event | Restricted Stock Units
Subsequent Event [Line Items]
Restricted stock granted | shares		657,998
Vesting period		3 years
Subsequent Event | State Bank Financial Corporation
Subsequent Event [Line Items]
Purchase price consideration		$ 826,000,000
Subsequent Event | State Bank Financial Corporation | Common Class A
Subsequent Event [Line Items]
Common stock in exchange for outstanding common shares | shares		1.271