CONSOLIDATED CONDENSED BALANCE SHEETS (UNAUDITED) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2012	Dec. 31, 2011
ASSETS
Property and Equipment, Accumulated Depreciation	$ 117,712	$ 104,541
STOCKHOLDERS' EQUITY:
Common stock, par value (in dollars per share)	$ 1	$ 1
Common stock, shares authorized (in shares)	75,000,000	75,000,000
Common stock, shares issued (in shares)	47,367,950	47,329,275
Common stock, shares outstanding (in shares)	47,367,950	47,329,275