Stockholders' Equity - Dividends (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Per Share
Common Stock (in USD per share)	$ 0.87	$ 0.8700
Series I Preferred Stock (in USD per share)		$ 0.8125
Amount
Common Stock	$ 344,760	$ 323,726
Series I Preferred Stock	0	11,676
Totals	$ 344,760	$ 335,402

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

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Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

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Amount of cash outflow in the form of ordinary dividends to preferred shareholders of the parent entity.

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Cash outflow in the form of ordinary dividends to common shareholders, preferred shareholders and noncontrolling interests, generally out of earnings.

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

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