Number of prorata shares.

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Number of stock issued during the period as per commitment.

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Aggregate dividends declared during the period for each share of common stock outstanding.

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Face amount or stated value per share of common stock.

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The maximum number of common shares permitted to be issued by an entity's charter and bylaws.

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The number of new shares issued in the conversion of stock in a noncash (or part noncash) transaction. Noncash is defined as transactions during a period that do not result in cash receipts or cash payments in the period. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

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Amount of paid and unpaid common stock dividends declared with the form of settlement in cash.

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Carrying value as of the balance sheet date of dividends declared but unpaid on equity securities issued by the entity and outstanding.

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Cash outflow in the form of capital distributions and dividends to common shareholders, preferred shareholders and noncontrolling interests.

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The cash outflow for cost incurred directly with the issuance of an equity security.

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The cash inflow from the additional capital contribution to the entity.

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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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Number of new stock issued during the period.

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STOCKHOLDERS' EQUITY - Dividends (Details) - USD ($) $ / shares in Units, $ in Millions														1 Months Ended	12 Months Ended
	Jan. 25, 2021	Dec. 14, 2020	Jul. 31, 2020	Feb. 26, 2020	Oct. 24, 2019	Aug. 02, 2019	May 03, 2019	Feb. 15, 2019	Nov. 01, 2018	Sep. 14, 2018	Jul. 24, 2018	May 03, 2018	Feb. 28, 2018	Jan. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 11, 2020	Nov. 10, 2020	Oct. 20, 2020	Sep. 24, 2020
Dividends
Cash dividend declared (in dollars per share)				$ 0.03	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 0.20	$ 1.55	$ 0.20	$ 0.20	$ 0.20
Dividends declared				$ 3.2	$ 21.0	$ 21.3	$ 21.3	$ 21.3	$ 21.2	$ 162.9	$ 25.8	$ 26.0	$ 26.0
Dividends and dividend equivalents															$ 6.5	$ 84.1	$ 258.1
Accrued unpaid dividends															$ 0.4	$ 2.3	4.0
Class A common stock
STOCKHOLDERS' EQUITY
Number of shares authorized															524,173,073	524,173,073
Sell price per share															$ 0.01	$ 0.01
Gross proceeds															$ 264.7
Dividends
Dividends and dividend equivalents															1.6	$ 41.7	122.0
Class A common stock \| Mudrick Capital Management LP [Member]
STOCKHOLDERS' EQUITY
Number of shares issued		21,978,022
Consideration received for commitment fee		8,241,758
Class A common stock \| Equity Distribution Agreement [Member]
STOCKHOLDERS' EQUITY
Number of shares authorized																		178,000,000.0	20,000,000	15,000,000	15,000,000
Sell price per share																		$ 0.01	$ 0.01	$ 0.01	$ 0.01
Gross proceeds															$ 272.8
Number of shares issued															90,955,685
Sales agents fees paid															$ 8.1
Class A common stock \| Equity Distribution Agreement [Member] \| Subsequent Events
STOCKHOLDERS' EQUITY
Sell price per share	$ 0.01
Gross proceeds	$ 582.0													$ 596.9
Number of shares issued	50,000,000													187,066,293
Sales agents fees paid														$ 14.9
Class B common stock
STOCKHOLDERS' EQUITY
Number of shares authorized															51,769,784	51,769,784
Sell price per share															$ 0.01	$ 0.01
Dividends
Dividends and dividend equivalents															$ 1.6	$ 41.4	136.1
Dividend Equivalents
Dividends
Dividends and dividend equivalents															$ 3.3	$ 1.0	$ 0.1
10.5 % First Lien Notes due 2026 \| Class A common stock
STOCKHOLDERS' EQUITY
Number of Prorata Shares			5,000,000												5,000,000
Second Lien Notes due 2026 \| Mudrick Capital Management LP [Member]
STOCKHOLDERS' EQUITY
Consideration received for conversion		13,736,264