Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Sources of income from continuing operations before income taxes
U.S. operations	$ 2,230	$ 2,433	$ 2,047
Non-U.S. operations	154,275	125,810	109,590
Income from continuing operations before income taxes and earnings of unconsolidated equity method investment	$ 156,505	$ 128,243	$ 111,637