Debt (Bank of America Digital Projector Loan) (Narrative) (Details) - USD ($) $ in Thousands		3 Months Ended	12 Months Ended
	Feb. 05, 2018	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Contractual facility		$ 275,511	$ 271,732
Bank Of America Digital Projector Loan [Member]
Debt Instrument [Line Items]
Contractual facility	$ 4,600
Interest rate	5.00%