Summary of Significant Accounting Policies Summary of Significant Accounting Policies (Details) - $ / shares	Apr. 26, 2016	Mar. 31, 2016	Dec. 31, 2015
Subsequent Event [Line Items]
Common stock, par value (usd per share)		$ 5.00	$ 5.00
Common stock, shares authorized		75,000,000	75,000,000
Subsequent Event
Subsequent Event [Line Items]
Common stock, shares authorized	150,000,000