CONSOLIDATED STATEMENTS OF INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Revenues	$ 176,561	$ 153,744	$ 325,125	$ 301,402
Cost of sales	122,913	114,411	227,113	219,684
Gross profit	53,648	39,333	98,012	81,718
Selling, general and administrative and other operating expenses	18,728	15,457	35,681	32,451
Start-up costs	811		811
Operating profit	34,109	23,876	61,520	49,267
Other income, net	200	212	292	325
Income before income taxes	34,309	24,088	61,812	49,592
Income taxes	11,292	7,781	20,368	15,709
Net income	$ 23,017	$ 16,307	$ 41,444	$ 33,883
Earnings per share:
Basic	$ 1.00	$ 0.71	$ 1.79	$ 1.47
Diluted	$ 1.00	$ 0.71	$ 1.79	$ 1.47
Other information:
Dividends declared per common share (See Note 4)			$ 0.60	$ 0.54