Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]
Net income	$ 8,626	$ 10,492
Basic-weighted average shares outstanding	27,349,000	28,127,000
Effect of dilutive potential securities	505,000	373,000
Diluted- weighted average shares outstanding	27,854,000	28,500,000
Basic (per share)	$ 0.32	$ 0.37
Diluted (per share)	$ 0.31	$ 0.37
Shares excluded from computation of earnings per share	0	300,000