Subsequent Events (Narrative) (Details) - $ / shares		3 Months Ended
	Oct. 05, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015
Subsequent Event [Line Items]
Dividend paid to common stockholders	$ 0.36	$ 0.36	$ 0.36	$ 0.32	$ 0.32	$ 0.32	$ 0.29
Dividends payable, date of record	Sep. 20, 2016	Jun. 17, 2016	Mar. 18, 2016	Dec. 17, 2015	Jun. 19, 2015	Mar. 20, 2015	Dec. 19, 2014
Dividends payable, date payable	Oct. 05, 2016	Jul. 06, 2016	Apr. 05, 2016	Jan. 06, 2016	Jul. 08, 2015	Apr. 07, 2015	Jan. 07, 2015
Subsequent Event [Member]
Subsequent Event [Line Items]
Dividend paid to common stockholders	$ 0.36
Dividends payable, date of record	Sep. 20, 2016
Dividends payable, date payable	Oct. 05, 2016