Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Per Share data, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stockholders' equity:
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000	200,000
Common stock, shares issued (in shares)	46,410	46,410
Common stock, shares outstanding (in shares)	41,176	43,284	43,076
Treasury stock, at cost (in shares)	5,234	3,126	3,334