CONSOLIDATED STATEMENT OF CHANGES IN STOCKHOLDERS' EQUITY - 9 months ended Sep. 30, 2016 - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings
Beginning Balance (in shares) at Dec. 31, 2015	65,637	65,637
Beginning Balance at Dec. 31, 2015	$ 115,806	$ 7	$ 100,929	$ 14,870
Net income	42,190			42,190
Restricted stock vestings (in shares)		385
Restricted stock vestings	135		135
Dividend equivalents cancelled upon forfeiture of performance-based restricted stock awards	27			27
Shares surrendered and cancelled upon vesting of restricted stock to satisfy tax withholdings (in shares)		(118)
Shares surrendered and cancelled upon vesting of restricted stock to satisfy tax withholdings	(2,105)		(2,105)
Stock-based compensation	4,402		4,402
Tax deductions relating to stock-based compensation	435		435
Shares issuable in lieu of dividend payments on unvested performance-based restricted stock awards	(162)		(162)
Issuance of common stock under employee stock purchase plan (in shares)		75
Issuance of common stock under employee stock purchase plan	1,114		1,114
Ending Balance at Sep. 30, 2016	$ 161,842	$ 7	$ 104,748	$ 57,087
Ending Balance (in shares) at Sep. 30, 2016	65,979	65,979