Business Segment and Geographic Information (Reconciliation to Consolidated Statements of Income (Loss)) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting [Abstract]
Operating income	$ 83,852	$ 76,255	$ 81,241
Equity income in unconsolidated joint ventures	4,146	2,890	4,123
Other income (expense), net	(1,788)	(8,492)	(1,194)
Interest income (expense), net	(3,930)	(4,480)	(2,946)
Income before income taxes	$ 82,280	$ 66,173	$ 81,224