Summary of Accounting Policies (Cash and Cash Equivalents) (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 29,122	$ 23,728	$ 31,649	$ 10,300
Cash and cash equivalents which exceeded federally-insured limits	17,600
Cash held in foreign banks
Cash and Cash Equivalents [Line Items]
Cash and cash equivalents	$ 10,900	$ 4,500