Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Noncontrolling Interest [Member]	Total
Beginning balance at Dec. 31, 2016	$ 510	$ 893,102	$ (11,542)	$ (491,805)	$ (22,268)		$ 367,997
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				176,100			176,100
Net income							176,100
Other comprehensive income (loss), net of income taxes					(4,424)		(4,424)
Payment of dividends		745	(1,711)	(163,465)			(164,431)
Exercise of stock options		65					65
Restricted stock units and stock options surrendered	2	(3,793)					(3,791)
Stock-based compensation expense		6,640					6,640
Ending balance at Dec. 31, 2017	512	896,759	(13,253)	(479,170)	(26,692)		378,156
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				264,670			264,670
Net income							264,670
Tax benefit or Translation adjustment related to adoption of ASU (ASU 2014-09 [Member]) at Dec. 31, 2018				(134)			(134)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss), net of income taxes					(1,332)		(1,332)
Payment of dividends		514	(1,930)	(173,890)			(175,306)
Exercise of stock options		11					11
Restricted stock units and stock options surrendered	1	(4,145)					(4,144)
Stock-based compensation expense		7,656					7,656
Establishment of noncontrolling interest in consolidated joint venture						$ 287,433
Ending balance at Dec. 31, 2018	$ 513	900,795	(15,183)	(388,524)	(28,024)	287,433	469,577
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income				145,794		(17,500)	145,794
Adjustment of noncontrolling interest to redemption value				(68,054)		68,054	(68,054)
Net income							128,294
Tax benefit or Translation adjustment related to adoption of ASU (ASU 2018-02 [Member]) at Dec. 31, 2019				2,707	(2,707)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Other comprehensive income (loss), net of income taxes					2,572		2,572
Purchase of additional ownership interest in consolidated joint venture		(2,899)				(2,582)	(2,899)
Payment of dividends		532	(2,132)	(187,437)			(189,037)
Exercise of stock options		35					35
Distribution from consolidated joint venture						(113,894)
Issuance of Company's common stock		282,873					$ 282,908
Issuance of Company's common stock (in shares)	35						3,500
Restricted stock units and stock options surrendered	$ 1	(4,001)					$ (4,000)
Stock-based compensation expense		7,833					7,833
Ending balance at Dec. 31, 2019	$ 549	$ 1,185,168	$ (17,315)	$ (495,514)	$ (28,159)	$ 221,511	$ 644,729