Earnings Per Share (Schedule Computing Earnings Per Share and Weighted Average Number of Shares) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Earnings Per Share [Abstract]
Net income/ (loss) attributable to the Company	$ 11,219	$ (7,379)	$ 21,840	$ 4,132
Weighted average number of shares:
Weighted average number of shares used in calculating basic net income/(loss) per share	31,832	31,628	31,809	31,562
Effect of dilutive stock-based compensation plans:
Stock options	103		104	125
Weighted average number of shares used in calculating diluted net income per share	31,935	31,628	31,913	31,687
Average market price of common stock used for calculation of dilutive shares	$ 36.23	$ 30.59	$ 35.97	$ 28.53
Net income/(loss) per share:
Basic	$ 0.35	$ (0.23)	$ 0.69	$ 0.13
Diluted	$ 0.35	$ (0.23)	$ 0.68	$ 0.13