CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, except Share data	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Total
Balances at Dec. 31, 2010	$ 2	$ 127,064	$ 55,043	$ 18,075	$ (2,510)	$ 197,674
Balances (shares) at Dec. 31, 2010	19,295,000
Net income			50,189	625		50,814
Foreign currency translation adjustments					(871)	(871)
Stock based compensation		1,119				1,119
Balances at Dec. 31, 2011	2	128,183	105,232	18,700	(3,381)	248,736
Balances (shares) at Dec. 31, 2011	19,295,000
Net income			63,465	816		64,281
Foreign currency translation adjustments					464	464
Deconsolidation of non-controlling interest		49		(19,516)		(19,467)
Issuance of common stock, net of underwriting discount and offering expenses		51,543				51,543
Issuance of common stock, net of underwriting discount and offering expenses (in shares)	2,757,000					2,757,170
Stock based compensation		1,288				1,288
Balances at Dec. 31, 2012	2	181,063	168,697		(2,917)	346,845
Balances (shares) at Dec. 31, 2012	22,052,000					22,052,529
Net income			63,926	594		64,520
Foreign currency translation adjustments					561	561
Exercise of stock options		1,524				1,524
Exercise of stock options (shares)	160,000
Stock issuance costs		(155)				(155)
Stock based compensation -options		1,429				1,429
Stock based compensation - restricted stock		107				107
Stock based compensation - restricted stock (shares)	28,000
Excess tax benefit from share-based compensation awards		295				295
Balances at Dec. 31, 2013	$ 2	$ 184,263	$ 232,623	$ 594	$ (2,356)	$ 415,126
Balances (shares) at Dec. 31, 2013	22,240,000					22,240,673