Stockholders' Equity - Dividends Declared (Details) - $ / shares	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Dividends declared (in dollars per share)	$ 0.46	$ 0.46	$ 0.46	$ 0.46	$ 0.46	$ 0.46	$ 0.46	$ 0.46
Common stock
Class of Stock [Line Items]
Dividends declared (in dollars per share)	$ 0.46								$ 1.84	$ 1.84	$ 1.84
Series A Preferred Stock
Class of Stock [Line Items]
Dividends declared (in dollars per share)											1.19
Series B Preferred Stock
Class of Stock [Line Items]
Dividends declared (in dollars per share)									2.00	2.00	2.00
Series C Preferred Stock
Class of Stock [Line Items]
Dividends declared (in dollars per share)									$ 0.72	$ 2.00	$ 2.00