CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (Unaudited) Statement - USD ($) $ in Thousands	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Treasury Stock [Member]
Common stock, issued		103,130,300				31,943,599
Additional paid-in capital			$ 715,475
Retained earnings				$ 997,250
Accumulated other comprehensive income					$ 1,388
Total stockholders’ equity	$ 407,927	$ 10,313				$ (1,316,499)
Net income	38,066			38,066
Total other comprehensive income (loss)	(423)				(423)
Issuance of shares of common stock (in shares)		90,009
Issuance of shares of common stock, amount	3,711	$ 9	3,702
Issuance of restricted stock units and net share settlement related to withholding taxes (in shares)		58,829
Issuance of restricted stock units and net share settlement related to withholding taxes, amount	(3,284)	$ 6	(3,290)
Repurchase of common stock (in shares)						473,376
Repurchase of common stock, amount	(50,000)					$ (50,000)
Stock-based compensation	8,865		8,865
Net income	97,282
Total other comprehensive income (loss)	(1,317)
Common stock, issued		103,279,138				32,416,975
Additional paid-in capital			724,752
Retained earnings				1,035,316
Accumulated other comprehensive income					965
Total stockholders’ equity	404,862	$ 10,328				$ (1,366,499)
Net income	59,217			59,217
Total other comprehensive income (loss)	(895)				(895)
Issuance of shares of common stock (in shares)		15,902
Issuance of shares of common stock, amount	759	$ 2	757
Issuance of restricted stock units and net share settlement related to withholding taxes (in shares)		100,643
Issuance of restricted stock units and net share settlement related to withholding taxes, amount	(6,341)	$ 10	(6,351)
Repurchase of common stock (in shares)						1,175,531
Repurchase of common stock, amount	(100,000)					$ (100,000)
Stock-based compensation	6,335		6,335
Common stock, issued		103,395,683				33,592,506
Additional paid-in capital			725,493
Retained earnings				1,094,533
Accumulated other comprehensive income					70
Total stockholders’ equity	$ 363,937	$ 10,340				$ (1,466,499)
Common stock, issued	103,642,292	103,642,292				35,017,726
Additional paid-in capital	$ 739,099		739,099
Retained earnings	1,259,984			1,259,984
Accumulated other comprehensive income	336				336
Total stockholders’ equity	393,285	$ 10,365				$ (1,616,499)
Net income	46,284			46,284
Total other comprehensive income (loss)	(3,102)				(3,102)
Issuance of shares of common stock (in shares)		17,783
Issuance of shares of common stock, amount	935	$ 2	933
Issuance of restricted stock units and net share settlement related to withholding taxes (in shares)		57,451
Issuance of restricted stock units and net share settlement related to withholding taxes, amount	(3,394)	$ 5	(3,399)
Repurchase of common stock (in shares)						382,279
Repurchase of common stock, amount	(50,000)					$ (50,000)
Stock-based compensation	9,275		9,275
Net income	84,559
Total other comprehensive income (loss)	637
Common stock, issued		103,717,526				35,400,005
Additional paid-in capital			745,908
Retained earnings				1,306,268
Accumulated other comprehensive income					(2,766)
Total stockholders’ equity	393,283	$ 10,372				$ (1,666,499)
Net income	38,275			38,275
Total other comprehensive income (loss)	3,739				3,739
Issuance of shares of common stock (in shares)		31,857
Issuance of shares of common stock, amount	1,941	$ 3	1,938
Issuance of restricted stock units and net share settlement related to withholding taxes (in shares)		39,155
Issuance of restricted stock units and net share settlement related to withholding taxes, amount	(2,619)	$ 4	(2,623)
Repurchase of common stock (in shares)						418,019
Repurchase of common stock, amount	(50,000)					$ (50,000)
Stock-based compensation	$ 7,559		7,559
Common stock, issued	103,788,538	103,788,538				35,818,024
Additional paid-in capital	$ 752,782		$ 752,782
Retained earnings	1,344,543			$ 1,344,543
Accumulated other comprehensive income	973				$ 973
Total stockholders’ equity	$ 392,178	$ 10,379				$ (1,716,499)