Accounts Receivable Grants from Outside Parties (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017
GRANTS FROM OUTSIDE PARTIES: [Abstract]
Grant proceeds received from outside parties			$ 12,900	$ 11,600
Amortization of deferred grants	$ 3,136	$ 3,065	$ 5,603	$ 6,310