Accounts Receivable Grants from Outside Parties (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
GRANTS FROM OUTSIDE PARTIES: [Abstract]
Grant proceeds received from outside parties	$ 5,900	$ 4,800
Amortization of deferred grants	$ 2,467	$ 3,245