Net Income per Share (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2018	Mar. 31, 2017
Net Income per Share [Abstract]
Net income	[1]	$ 2,132	$ 7,414
Less earnings allocated to RSUs		(50)	(179)
Net income available to common shareholders		$ 2,082	$ 7,235

[1] There is no material difference between net income and comprehensive income.