Consolidated Statements of Changes in Equity (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Statement Of Stockholders Equity [Abstract]
Amortization of terminated hedge, income tax effect	$ 60	$ 120	$ 120
Unrealized loss on marketable security, income tax effect	(831)
Unrealized derivative gains and losses on cash flow hedges, income tax effect	536	2,283	6,529
Minimum pension liability, income tax effect	$ (5,003)	$ (817)	$ 5,356