Aggregate value of common shares reserved for future issuance.

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- Definition

Minimum Number of Quarters with No Dividends that Results in Voting Rights

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- Definition

Preferred Stock, Percentage of Stock Holders Required for Term Changes

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- Definition

Preferred Stock, Redemption Term

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- Definition

Preferred Stock, Voting Rights, Number of Additional Directors Elected

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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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- Definition

Face amount or stated value per share of common stock.

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- Definition

Monetary value of common stock allocated to investors to buy shares of a new issue of common stock before they are offered to the public. When stock is sold on a subscription basis, the issuer does not initially receive the total proceeds. In general, the issuer does not issue the shares to the investor until it receives the entire proceeds.

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- Definition

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

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No definition available.

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- Definition

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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=84159872&loc=d3e21475-112644

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-Publisher FASB
-Name Accounting Standards Codification
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- Definition

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 price per share at which the preferred stock of an entity that has priority over common stock in the distribution of dividends and in the event of liquidation of the entity is redeemed or may be called at. The redemption features of this preferred stock are solely within the control of the issuer.

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- Definition

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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- Definition

Total number of nonredeemable preferred shares (or preferred stock redeemable solely at the option of the issuer) issued to shareholders (includes related preferred shares that were issued, repurchased, and remain in the treasury). May be all or portion of the number of preferred shares authorized. Excludes preferred shares that are classified as debt.

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- Definition

Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased.

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- Definition

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

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
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Proceeds from issuance of capital stock which provides for a specific dividend that is paid to the shareholders before any dividends to common stockholders and which takes precedence over common stockholders in the event of liquidation.

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- Definition

Price of a single share of a number of saleable stocks of a company.

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No definition available.

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- Definition

Number of new stock issued during the period.

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Stockholders' Equity - Narrative (Details) $ / shares in Units, $ in Millions					3 Months Ended		12 Months Ended
	Oct. 15, 2017	Oct. 13, 2017 USD ($) $ / shares shares	Apr. 22, 2015 USD ($) $ / shares shares	Jun. 04, 2013 USD ($) $ / shares shares	Mar. 31, 2018 USD ($) $ / shares shares	Mar. 31, 2017 USD ($) $ / shares shares	Dec. 31, 2017 director quarter $ / shares shares	Aug. 10, 2017 USD ($) $ / shares	Mar. 20, 2015 USD ($)
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)					200,000,000		200,000,000
Preferred stock, par value (in dollars per share) \| $ / shares					$ 0.01		$ 0.01
Preferred stock, shares issued (in shares)					12,000,000		12,000,000
Preferred stock, shares outstanding (in shares)							12,000,000
Common stock, par value (in dollars per share) \| $ / shares					$ 0.01		$ 0.01
Equity Distribution Agreements
Class of Stock [Line Items]
Shares issued (in shares)					0
Common stock, par value (in dollars per share) \| $ / shares								$ 0.01
Common stock that may be sold (up to) \| $								$ 100.0	$ 39.3
Common stock reserved for issuance \| $					$ 99.6
Prior Equity Distribution Agreement
Class of Stock [Line Items]
Shares issued (in shares)					0	87,737
Share price (in dollars per share) \| $ / shares						$ 6.68
Proceeds from issuance of common stock \| $						$ 0.6
Series B Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)					6,000,000		6,000,000
Preferred stock, par value (in dollars per share) \| $ / shares				$ 0.01	$ 0.01		$ 0.01
Preferred stock, shares issued (in shares)					3,000,000		3,000,000
Preferred stock, shares outstanding (in shares)					3,000,000		3,000,000
Shares issued (in shares)				3,000,000
Preferred stock, cumulative redeemable dividend rate				7.75%	7.75%		7.75%
Preferred stock, liquidation preference per share (in dollars per share) \| $ / shares				$ 25	$ 25		$ 25
Preferred stock issuance, net \| $				$ 72.4
Redemption term					120 days
Redemption price (in dollars per share) \| $ / shares					$ 25.00
Series C Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)					4,140,000		4,140,000
Preferred stock, par value (in dollars per share) \| $ / shares			$ 0.01		$ 0.01		$ 0.01
Preferred stock, shares issued (in shares)			3,600,000		3,600,000		3,600,000
Preferred stock, shares outstanding (in shares)					3,600,000		3,600,000
Preferred stock, cumulative redeemable dividend rate			7.875%		7.875%		7.875%
Preferred stock, liquidation preference per share (in dollars per share) \| $ / shares			$ 25		$ 25		$ 25
Preferred stock issuance, net \| $			$ 86.9
Redemption term					120 days
Redemption price (in dollars per share) \| $ / shares					$ 25.00
Series D Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares authorized (in shares)					5,750,000		5,750,000
Preferred stock, par value (in dollars per share) \| $ / shares		$ 0.01			$ 0.01		$ 0.01
Preferred stock, shares issued (in shares)		5,400,000			5,400,000		5,400,000
Preferred stock, shares outstanding (in shares)					5,400,000		5,400,000
Preferred stock, cumulative redeemable dividend rate	5.695%	8.00%			8.00%		8.00%
Preferred stock, liquidation preference per share (in dollars per share) \| $ / shares		$ 25			$ 25.00		$ 25
Preferred stock issuance, net \| $		$ 130.5
Redemption term					120 days
Redemption price (in dollars per share) \| $ / shares					$ 25.00
Series B, Series C and Series D Preferred Stock
Class of Stock [Line Items]
Number of quarters with no dividends that results in voting rights \| quarter							6
Number of elected directors pending preferred stock voting rights \| director							2
Stockholders required for term changes, percentage					66.67%