Stockholders' Equity (Stock Transactions - Narrative) (Details) - $ / shares		3 Months Ended		6 Months Ended
	Aug. 01, 2017	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Jul. 31, 2017	May 02, 2017	May 01, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Common stock, authorized shares		300,000,000		300,000,000					150,000,000
Dividends declared per common share, during the period (in dollars per share)		$ 0.30	$ 0.30	$ 0.60	$ 0.60
Common Stock
Class of Stock [Line Items]
Common stock, authorized shares							300,000,000	150,000,000
At The Market Equity Offering Program
Class of Stock [Line Items]
Issuance of common stock (shares)				0
Subsequent Event
Class of Stock [Line Items]
Dividends declared per common share, during the period (in dollars per share)	$ 0.30
Subsequent Event | At The Market Equity Offering Program
Class of Stock [Line Items]
Number of authorized shares remaining under offering program (shares)						5,868,697