Stockholders' Equity - Common Stock Dividends (Details) - $ / shares	1 Months Ended	3 Months Ended						9 Months Ended
	Nov. 30, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Sep. 30, 2016	Sep. 30, 2015
Stockholders' Equity
Common stock dividends declared (in dollars per share)	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.15	$ 0.15
Common stock dividends paid (in dollars per share)		$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05	$ 0.05