CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Retained Earnings	Accumulated Other Comprehensive (Loss) Income	Treasury Stock	Non-controlling Interest	Total
Beginning Balance (in shares) at Dec. 31, 2016	74,342,826
Beginning Balance at Dec. 31, 2016	$ 572,040	$ 94,746	$ 2,507		$ 17,506	$ 686,799
Increase (Decrease) in Stockholders' Equity
Capital contribution from non-controlling interest					193	193
Capital distribution to non-controlling interest					(2,330)	(2,330)
Stock based compensation expense	$ 76					76
Stock based compensation expense (in shares)	5,334
Repurchase of common shares				$ (147,422)		(147,422)
Repurchase of common shares (in shares)	(8,450,294)
Retirement of treasury stock	$ (147,422)			147,422
Other comprehensive income (loss)			(3,968)			(3,968)
Net income		59,578			(342)	59,236
Ending Balance at Dec. 31, 2017	$ 424,694	154,324	(1,461)		15,027	592,584
Ending Balance (in shares) at Dec. 31, 2017	65,897,866
Increase (Decrease) in Stockholders' Equity
Allocation of ownership interest	$ (490)				490
Additional ownership interest	297				(297)
Capital contribution from non-controlling interest					887	887
Capital distribution to non-controlling interest					(400)	(400)
Stock based compensation expense	$ 71					71
Stock based compensation expense (in shares)	2,778
Issuance of common stock for officer compensation, net of tax withholding	$ 192					192
Issuance of common stock for officer compensation, net of tax withholding (in shares)	9,956
Repurchase of common shares				(93,369)		(93,369)
Repurchase of common shares (in shares)	(5,238,566)
Retirement of treasury stock	$ (93,369)			93,369
Adoption of ASU 2018-02 Income Statement - Reporting Comprehensive Income		313	(313)
Other comprehensive income (loss)			787			787
Other comprehensive (loss) income, net of tax, excluding adoption of ASUs			404			404
Net income		32,369			(767)	31,602
Ending Balance at Dec. 31, 2018	$ 331,395	187,450	(674)		14,940	$ 533,111
Ending Balance (in shares) at Dec. 31, 2018	60,672,034					60,672,034
Increase (Decrease) in Stockholders' Equity
Adoption of ASU, net of tax | ASU 2014-09		1,140				$ 1,140
Adoption of ASU, net of tax | ASU 2016-01		(696)	696
Allocation of ownership interest	$ (1,209)				1,209
Additional ownership interest	(3,787)				(7,832)	(11,619)
Capital contribution from non-controlling interest					2,546	2,546
Capital distribution to non-controlling interest					(600)	(600)
Stock based compensation expense	$ 77					77
Stock based compensation expense (in shares)	5,708
Repurchase of common shares				(20,845)		(20,845)
Repurchase of common shares (in shares)	(1,263,159)
Retirement of treasury stock	$ (20,845)			$ 20,845
Other comprehensive income (loss)			339			339
Net income		26,775			(114)	26,661
Ending Balance at Dec. 31, 2019	$ 305,631	$ 214,225	$ (335)		$ 10,149	$ 529,670
Ending Balance (in shares) at Dec. 31, 2019	59,414,583					59,414,583