Operating Expenses (Schedule of Direct Operating Expenses) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Expenses [Abstract]
Employee compensation expenses	$ 35,440	$ 27,856	$ 22,855
Buildings, facilities and technology expenses	8,359	7,966	7,179
Travel, advertising and promotion expenses	23,994	23,688	22,150
Other costs of services	11,220	6,552	3,842
Cost of Services, Total	$ 79,013	$ 66,062	$ 56,026