Earnings Per Share Data (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Shares used in the denominators of the basic and diluted earnings per share computations
Shares for basic per share computation - weighted average common shares outstanding	49,631	49,374
Dilutive effect of common stock equivalents	616	815
Shares for diluted per share computation	50,247	50,189
Options and stock appreciation rights ("SARs") excluded from computation as anti-dilutive because they are out-of-the-money	2,677	1,581
Unvested restricted stock and restricted stock units ("RSUs") considered to be participating securities	383	253
Effect (decrease) of allocation of undistributed earnings (net income) to the participating securities under the two class method:
Basic earnings per share	$ 0.00	$ 0
Diluted earnings per share	$ 0	$ 0