Deferred Issuance Costs Reclassified to Retained Earnings

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Depository Shares to Preferred Stock Ratio

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The percentage rate used to calculate dividend payments on preferred stock.

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The per share liquidation preference (or restrictions) of nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) that has a preference in involuntary liquidation considerably in excess of the par or stated value of the shares. The liquidation preference is the difference between the preference in liquidation and the par or stated values of the share.

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Face amount or stated value per share of preferred stock nonredeemable or redeemable solely at the option of the issuer.

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The maximum number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) permitted to be issued by an entity's charter and bylaws.

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Number of stock bought back by the entity at the exercise price or redemption price.

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Equity impact of the value of stock bought back by the entity at the exercise price or redemption price.

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Total cost of shares repurchased divided by the total number of shares repurchased.

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STOCKHOLDERS' EQUITY - Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Millions			12 Months Ended
	Aug. 23, 2019	Sep. 17, 2018	Dec. 31, 2019	Dec. 31, 2018
Series D 7.375% non-cumulative perpetual
Class of Stock [Line Items]
Depository shares to preferred stock ratio	2.50%
Series E 7.00% non-cumulative perpetual
Class of Stock [Line Items]
Depository shares to preferred stock ratio	2.50%
Preferred Stock
Class of Stock [Line Items]
Preferred stock, authorized (in shares)			197,106	240,000
Preferred stock, par value (in dollars per share)			$ 0.01
Preferred stock, liquidation preference per share (in dollars per share)			$ 1,000
Aggregate amount of redemption		$ 40.3
Preferred Stock \| Series D Depository shares
Class of Stock [Line Items]
Outstanding shares redeemed (shares)	734,823
Redemption price ( in dollars per share)	$ 1,000
Aggregate amount of redemption	$ 19.4
Preferred Stock \| Series D 7.375% non-cumulative perpetual
Class of Stock [Line Items]
Preferred stock, authorized (in shares)			96,629
Outstanding shares redeemed (shares)	18,371
Stock issuance cost	$ 1.7
Non cumulative preferred stock, dividend rate (percent)			7.375%	7.375%
Preferred Stock \| Series E Depository shares
Class of Stock [Line Items]
Outstanding shares redeemed (shares)	980,928
Redemption price ( in dollars per share)	$ 1,000
Aggregate amount of redemption	$ 26.6
Preferred Stock \| Series E 7.00% non-cumulative perpetual
Class of Stock [Line Items]
Preferred stock, authorized (in shares)			100,477
Outstanding shares redeemed (shares)	24,523
Stock issuance cost	$ 3.4
Non cumulative preferred stock, dividend rate (percent)			7.00%	7.00%
Preferred Stock \| Series C Depository shares
Class of Stock [Line Items]
Outstanding shares redeemed (shares)		1,610,000
Redemption price ( in dollars per share)		$ 25
Stock issuance cost		$ 2.3
Preferred Stock \| Series C 8.00% non-cumulative perpetual
Class of Stock [Line Items]
Outstanding shares redeemed (shares)		40,250
Redemption price ( in dollars per share)		$ 1,000
Non cumulative preferred stock, dividend rate (percent)		8.00%
Maximum \| Preferred Stock
Class of Stock [Line Items]
Preferred stock, authorized (in shares)			50,000,000