Condensed Consolidated Statements of Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Cumulative Effect, Period of Adoption, Adjustment [Member] Common Stock [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Additional Paid-in Capital [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] AOCI Attributable to Parent [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Parent [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member] Noncontrolling Interest [Member]	Cumulative Effect, Period of Adoption, Adjustment [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Common Stock [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Additional Paid-in Capital [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Retained Earnings [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] AOCI Attributable to Parent [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Parent [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member] Noncontrolling Interest [Member]	Cumulative Effect, Period of Adoption, Adjusted Balance [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Parent [Member]	Noncontrolling Interest [Member]	Total
Balance (in shares) at Dec. 31, 2018	50,700														50,700
Balance at Dec. 31, 2018	$ 0	$ 0	$ (58)	$ 0	$ (58)	$ 0	$ (58)	$ 51	$ 901,363	$ 422,164	$ (3,799)	$ 1,319,779	$ 125,259	$ 1,445,038	$ 51	$ 901,363	$ 422,222	$ (3,799)	$ 1,319,837	$ 125,259	$ 1,445,096
Stock-based compensation															$ 0	2,360	0	0	2,360	0	2,360
Exercise of options by employees and directors (in shares)															52
Exercise of options by employees and directors															$ 0	0	0	0	0	0	0
Cash paid to noncontrolling interest															0	0	0	0	0	(4,146)	(4,146)
Cash dividend declared															0	0	(5,579)	0	(5,579)	0	(5,579)
Net income															0	0	25,946	0	25,946	1,855	27,801
Change in foreign currency translation adjustments															0	0	0	(1,026)	(1,026)	(322)	(1,348)
Change in respect of derivative instruments designated for cash flow hedge															0	0	0	22	22	0	22
Change in unrealized gains or losses in respect of the Company's share in derivative instruments of unconsolidated investment															0	0	0	(1,145)	(1,145)	0	(1,145)
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge, net															$ 0	0	0	(8)	(8)	0	(8)
Balance (in shares) at Mar. 31, 2019															50,752
Balance at Mar. 31, 2019															$ 51	903,723	442,531	(5,956)	1,340,349	122,646	1,462,995
Balance (in shares) at Dec. 31, 2019	51,032														51,032
Balance at Dec. 31, 2019	$ 0	$ 0	$ (755)	$ 0	$ (755)	$ 0	$ (755)	$ 51	$ 913,150	$ 487,118	$ (8,654)	$ 1,391,665	$ 122,990	$ 1,514,655	$ 51	913,150	487,873	(8,654)	1,392,420	122,990	1,515,410
Stock-based compensation															$ 0	1,989	0	0	1,989	0	1,989
Exercise of options by employees and directors (in shares)															4
Exercise of options by employees and directors															$ 0	0	0	0	0	0	0
Cash paid to noncontrolling interest															0	0	0	0	0	(3,007)	(3,007)
Cash dividend declared															0	0	(5,614)	0	(5,614)	0	(5,614)
Net income															0	0	26,033	0	26,033	3,543	29,576
Change in foreign currency translation adjustments															0	0	0	(258)	(258)	(387)	(645)
Change in respect of derivative instruments designated for cash flow hedge															0	0	0	13	13	0	13
Change in unrealized gains or losses in respect of the Company's share in derivative instruments of unconsolidated investment															0	0	0	(4,755)	(4,755)	0	(4,755)
Amortization of unrealized gains in respect of derivative instruments designated for cash flow hedge, net															0	0	0	(8)	(8)	0	(8)
Increase in noncontrolling interest															$ 0	0	0	0	0	1,447	1,447
Balance (in shares) at Mar. 31, 2020															51,036
Balance at Mar. 31, 2020															$ 51	$ 915,139	$ 507,537	$ (13,662)	$ 1,409,065	$ 124,586	$ 1,533,651