Consolidated Statements of Stockholders' Investment (Equity) (USD $) In Thousands, except Share data	Total	Common Stock	Additional Paid-In Capital	Retained Earnings (Deficit)
Balance at Dec. 31, 2010	$ 265,689	$ 301	$ 262,088	$ 3,300
Balance, shares at Dec. 31, 2010		30,146,805
Issuance of Common Stock, shares		560,976
Issuance of Common Stock	3,869	6	3,863
Share-based compensation	524		524
Net income (loss)	25,871			25,871
Balance at Dec. 31, 2011	295,953	307	266,475	29,171
Balance, shares at Dec. 31, 2011		30,707,781
Issuance of Common Stock, shares		3,663,716
Issuance of Common Stock	57,119	37	57,082
Share-based compensation	659		659
Excess tax benefit on share-based compensation	818		818
Net income (loss)	37,530			37,530
Balance at Dec. 31, 2012	392,079	344	325,034	66,701
Balance, shares at Dec. 31, 2012		34,371,497
Issuance of Common Stock, shares		3,192,949
Issuance of Common Stock	53,490	32	53,458
Share-based compensation	1,503		1,503
Excess tax benefit on share-based compensation	4,297		4,297
Net income (loss)	48,996			48,996
Balance at Dec. 31, 2013	$ 500,365	$ 376	$ 384,292	$ 115,697
Balance, shares at Dec. 31, 2013		37,564,446