Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Earnings Per Share [Abstract]
Net income/(loss) attributable to the Company	$ 10,367	$ (2,172)	$ 23,868	$ 10,041
Weighted average number of shares:
Weighted average number of shares used in calculating basic net income per share	32,093	31,999	32,067	31,941
Effect of dilutive stock-based compensation plans:
Stock options	38		39	74
Weighted average number of shares used in calculating diluted net income per share	32,131	31,999	32,106	32,015
Shares related to stock-based compensation plans that were not included in the computation of diluted earnings per share because to do so would be antidilutive		56
Average market price of common stock used for calculation of dilutive shares	$ 39.47	$ 40.12	$ 37.40	$ 38.76
Earnings/(loss) per share attributable to Company shareholders:
Basic	0.32	(0.07)	0.74	0.31
Diluted	$ 0.32	$ (0.07)	$ 0.74	$ 0.31