Stockholders' Equity (Schedule of Quarterly Dividends Declared and Paid) (Details) - USD ($) $ / shares in Units, $ in Thousands			3 Months Ended				12 Months Ended
	Apr. 10, 2015	Jan. 06, 2014	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2016
Class of Stock [Line Items]
Dividends paid per share	$ 2.00	$ 2.00	$ 0.5	$ 0.3	$ 0.3	$ 0.3	$ 1.4
Common Stock
Class of Stock [Line Items]
Payments of dividends	$ 48,200	$ 46,700	$ 12,359	$ 7,371	$ 7,363	$ 7,344	$ 34,437