Condensed Consolidated Statements of Equity (Unaudited) (USD $) In Thousands, unless otherwise specified	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Parent [Member]	Noncontrolling Interest [Member]	Total
Balance at Dec. 31, 2012	$ 46	$ 732,140	$ (44,326)	$ 651	$ 688,511	$ 7,096	$ 695,607
Balance (in Shares) at Dec. 31, 2012	45,431
Stock-based compensation		2,857			2,857		2,857
Cash paid to noncontrolling interest						(349)	(349)
Cash dividend declared, per share						5,151	5,151
Net income			20,126		20,126	407	20,533
Other comprehensive loss, net of related taxes:
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge (net of related tax)				(84)	(84)		(84)
Balance at Jun. 30, 2013	46	734,997	(24,200)	567	711,410	12,305	723,715
Balance (in Shares) at Jun. 30, 2013	45,431
Balance at Dec. 31, 2013	46	735,295	(3,088)	487	732,740	12,371	745,111
Balance (in Shares) at Dec. 31, 2013	45,461
Stock-based compensation		2,806			2,806		2,806
Exercise of options by employees and directors		741			741		741
Exercise of options by employees and directors (in Shares)	58
Cash paid to noncontrolling interest						(254)	(254)
Cash dividend declared, per share			(5,003)		(5,003)		(5,003)
Increase in noncontrolling interest						257	257
Net income			30,688		30,688	414	31,102
Other comprehensive loss, net of related taxes:
Change in unrealized gains or losses in respect of the Company's share in derivative instruments of unconsolidated investment (net of related tax of $0)				(4,088)	(4,088)		(4,088)
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge (net of related tax)				(72)	(72)		(72)
Balance at Jun. 30, 2014	$ 46	$ 738,842	$ 22,597	$ (3,673)	$ 757,812	$ 12,788	$ 770,600
Balance (in Shares) at Jun. 30, 2014	45,519