Stockholders' Equity Matters - Dividends Declared (Details) - USD ($) $ / shares in Units, $ in Thousands															3 Months Ended		9 Months Ended
	Sep. 30, 2016	Jul. 27, 2016	Jun. 24, 2016	May 25, 2016	Mar. 21, 2016	Feb. 18, 2016	Dec. 15, 2015	Oct. 29, 2015	Sep. 30, 2015	Aug. 27, 2015	Jun. 26, 2015	May 28, 2015	Mar. 20, 2015	Feb. 19, 2015	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Equity [Abstract]
Dividends Declared per Common Share (in dollars per share)		$ 0.485		$ 0.4850		$ 0.4850		$ 0.4850		$ 0.4750		$ 0.4750		$ 0.4750	$ 0.4852	$ 0.4751000	$ 1.4886	$ 1.4250
Dividends, Common Stock	$ 127,737		$ 127,469		$ 102,651		$ 102,438		$ 100,213		$ 100,119		$ 99,795				$ 360,076	$ 302,658