Summary of Significant Accounting Policies (Schedule of Earnings Per Share Reconciliation) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net Income (Loss)	$ 40,021	$ (311,395)
Basic weighted average common shares outstanding	65,188	58,360
Effect of dilutive instruments	590	0
Diluted weighted average common shares outstanding	65,778	58,360
Net Income (Loss) - basic (in dollars per share)	$ 0.61	$ (5.34)
Net Income (Loss) - diluted (in dollars per share)	$ 0.61	$ (5.34)