CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common Stock	Treasury Stock	Additional Paid-In Capital	Retained Earnings	Non-Controlling Interests	Total
BALANCE at Dec. 31, 2014	$ 411	$ (43,598)	$ 320,084	$ 29,384	$ 15,112	$ 321,393
BALANCE (in shares) at Dec. 31, 2014	41,123,365
BALANCE (in shares) at Dec. 31, 2014		(3,853,586)
Increase (Decrease) in Stockholders' Equity
Net income						$ 6,889
BALANCE (in shares) at Mar. 31, 2015						37,307,000
BALANCE at Dec. 31, 2014	$ 411	$ (43,598)	320,084	29,384	15,112	$ 321,393
BALANCE (in shares) at Dec. 31, 2014	41,123,365
BALANCE (in shares) at Dec. 31, 2014		(3,853,586)
Increase (Decrease) in Stockholders' Equity
Net income				49,364	8,076	57,440
Issuance of Stock:
Issuance of shares for options exercised including tax benefit		$ 3,728	966			4,694
Issuance of shares for options exercised including tax benefit (in shares)		(317,333)
Issuance of restricted stock & performance stock		$ 2,292	(626)			1,666
Issuance of restricted stock & performance stock (in shares)		(200,015)
Shares received in lieu of tax withholding payment on vested restricted stock		$ (937)				(937)
Shares received in lieu of tax withholding payment on vested restricted stock (in shares)		44,590
Tax benefit from vesting of restricted stock			284			284
Stock-based compensation			3,057			3,057
Dividends				(9,358)		(9,358)
Distribution to noncontrolling interests					(4,904)	(4,904)
Share repurchase		$ (8,330)				(8,330)
Share repurchase (in shares)		315,953
BALANCE at Dec. 31, 2015	$ 411	$ (46,845)	323,765	69,390	18,284	$ 365,005
BALANCE (in shares) at Dec. 31, 2015	41,123,365
BALANCE (in shares) at Dec. 31, 2015		(3,696,781)				(3,696,781)
Increase (Decrease) in Stockholders' Equity
Net income				9,755		$ 9,755
Issuance of Stock:
Issuance of shares for options exercised including tax benefit		$ 278	92			370
Issuance of shares for options exercised including tax benefit (in shares)		(21,244)
Issuance of restricted stock & performance stock		$ 851	1,125			1,976
Issuance of restricted stock & performance stock (in shares)		(65,086)
Shares received in lieu of tax withholding payment on vested restricted stock		$ (562)				(562)
Shares received in lieu of tax withholding payment on vested restricted stock (in shares)		18,506
Stock-based compensation			990			990
Dividends				(2,426)		(2,426)
Share repurchase		$ (2,840)				(2,840)
Share repurchase (in shares)		102,029
Acquisition of noncontrolling interests			15,910		$ 18,284	34,194
BALANCE at Mar. 31, 2016	$ 411	$ (49,118)	$ 310,062	$ 76,719		$ 338,074
BALANCE (in shares) at Mar. 31, 2016	41,123,365					37,392,000
BALANCE (in shares) at Mar. 31, 2016		(3,730,986)				(3,730,986)