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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period) and after allocation of earnings to participating securities.

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No definition available.

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Participating Securities, Distributed and Undistributed Earnings (Loss), Basic and Diluted

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No definition available.

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Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

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Amount of paid and unpaid preferred stock dividends declared with the form of settlement in cash, stock and payment-in-kind (PIK).

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

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The weighted average fair value of nonvested awards on equity-based plans excluding option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, revenue or profit achievement stock award plan) for which the employer is contingently obligated to issue equity instruments or transfer assets to an employee who has not yet satisfied service or performance criteria necessary to gain title to proceeds from the sale of the award or underlying shares or units.

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Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

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EPS Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Numerator:
Net income	$ 60,879	$ 87,132	$ 70,395	$ 83,395	$ 100,593	$ 63,805	$ 79,935	$ 78,060	$ 301,801	$ 322,393	$ 312,668
Dividends declared on preferred stock									(15,000)	(15,000)	(15,000)
Dividends, dividend equivalents and undistributed earnings allocated to participating securities									(1,864)	(1,708)	(1,628)
Net income to common stockholders - basic and diluted									$ 284,937	$ 305,685	$ 296,040
Denominator:
Weighted average common shares for basic and diluted earnings per share									418,934	388,357	371,122
Earnings per Common Share - Basic and Diluted	$ 0.13	$ 0.19	$ 0.17	$ 0.20	$ 0.24	$ 0.15	$ 0.20	$ 0.20	$ 0.68	$ 0.79	$ 0.80
Anti-dilutive securities excluded from diluted earnings per share calculations (in shares)									2,100
Restricted Stock Units
Denominator:
Weighted average grant date fair value (in dollars per share)	$ 6.78								$ 6.78