Preferred stock redemption price, accrued and unpaid dividends per share.

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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

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

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Total number of common shares of an entity that have been sold or granted to shareholders (includes common shares that were issued, repurchased and remain in the treasury). These shares represent capital invested by the firm's shareholders and owners, and may be all or only a portion of the number of shares authorized. Shares issued include shares outstanding and shares held in the treasury.

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- Definition

Date the declared dividend will be paid, in CCYY-MM-DD format.

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Date the dividend to be paid was declared, in CCYY-MM-DD format.

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- Definition

Date the holder must own the stock to be entitled to the dividend, in CCYY-MM-DD format.

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- Definition

Settlement date of the forward contract indexed to issuer's equity, in CCYY-MM-DD format.

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- Definition

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

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

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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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Date the preferred stock has been redeemed, in CCYY-MM-DD format.

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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 cash inflow from the additional capital contribution to the entity.

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- Definition

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

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Shareholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions				6 Months Ended
	Jul. 17, 2017	Jul. 13, 2017	Aug. 01, 2016	Jun. 30, 2017	Aug. 16, 2017	Dec. 31, 2016
Class Of Stock [Line Items]
Common stock, shares issued				85,572,000		85,316,000
Dividends payable, date declared				Jul. 13, 2017
Dividends payable, date to be paid				Aug. 21, 2017
Dividends payable, date of record				Aug. 11, 2017
Subsequent Event [Member]
Class Of Stock [Line Items]
Common stock, dividends declared		$ 0.05
Series B [Member]
Class Of Stock [Line Items]
Dividend rate percentage				7.25%
Liquidation preference, per share				$ 25.00		$ 25.00
Redemption price per share				$ 25.00
Redemption date				May 22, 2017
Series B [Member] \| Scenario, Forecast [Member]
Class Of Stock [Line Items]
Redemption price plus accrued and unpaid dividends per share					$ 25.47
Series B [Member] \| Subsequent Event [Member]
Class Of Stock [Line Items]
Redemption price per share	$ 25.00
Redemption date	Aug. 16, 2017
Preferred stock redeemed, shares	1.5
Preferred stock dividends declared		$ 0.453125
Forward Sales Agreements [Member]
Class Of Stock [Line Items]
Common stock, shares issued			5,750,000
Public offering, estimated net proceeds			$ 43.2
Settlement date of agreements				Aug. 01, 2017