Summary of Significant Accounting Policies (Other Assets) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Accounting Policies [Abstract]
Prepaid expenses	$ 5,216	$ 3,021
Deferred tax assets	28,630	26,670
Other	409	407
Other assets	$ 34,255	$ 30,098