Capital Stock - Textual (Details) - USD ($)		3 Months Ended
	Feb. 12, 2019	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	Mar. 05, 2020	Oct. 29, 2019	Oct. 22, 2019	Feb. 27, 2009
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)		40,040,000		40,040,000				40,040,000
Preferred stock, par value (in dollars per share)		$ 0.01		$ 0.01				$ 0.01
Preferred stock, shares issued (in shares)		767		767
Preferred stock, shares outstanding (in shares)		767		767
Number of shares authorized to be repurchased (in shares)					180,000,000		60,000,000
Stock repurchases (in shares)		130,916	4,922,336
Stock repurchases, average price (in dollars per share)		$ 23.53	$ 18.96
Maximum
Class of Stock [Line Items]
Preferred stock, liquidation preference, value								$ 80,000,000
Reliance Bancshares, Inc. | Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)	40,000
Preferred stock, par value (in dollars per share)	$ 0.01
Reliance Bancshares, Inc. | Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)	2,000.02
Preferred stock, par value (in dollars per share)	$ 0.01
Reliance Bancshares, Inc. | Convertible Preferred Stock
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)	$ 0.01
Preferred stock, dividend rate, percentage	7.00%
Reliance Bancshares, Inc. | Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)	140
Preferred stock, shares issued (in shares)						0
Preferred stock, shares outstanding (in shares)						0
Reliance Bancshares, Inc. | Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share)						$ 0.01