Common Stock Common Stock (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Shares Issued During Period, Value, Share-based Compensation	$ 1.2
Sales Agency Agreements Common Stock, Shares Authorized	200,000,000	200,000,000
Document Period End Date	Sep. 30, 2016
Shares Issued During Period, Share-based Compensation	300,000
Sales Agency Agreement [Member]
Class of Stock [Line Items]
Shares issued	1,600,000
Sales Agency Agreements Common Stock, Shares Authorized	3,800,000
Sales Agency Agreements Common Stock, Value, Issued	$ 65.6
Common Stock Shares Authorized Under Sales Agency Agreements Remaining Shares Authorized To Sell	2,200,000