CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
CONSOLIDATED BALANCE SHEETS
Accounts receivable, allowances (in dollars)	$ 1,168	$ 1,132
Property and equipment, accumulated depreciation (in dollars)	131,506	115,679
Intangible assets, accumulated amortization (in dollars)	$ 3,060	$ 2,893
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, authorized shares	4,000,000	4,000,000
Preferred stock, issued shares	0	0
Preferred stock, outstanding shares	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, authorized shares	100,000,000	100,000,000
Common stock, issued shares	21,322,196	21,223,076
Common stock, outstanding shares	21,322,196	21,223,076