Earnings per Share (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Computation of basic and diluted earnings per share
Net income	$ 6,950	$ 11,508	$ 16,341	$ 28,904
Net weighted average common shares outstanding, basic (in shares)	87,736,000	87,830,000	87,660,000	87,551,000
Weighted average common shares outstanding, diluted (in shares)	88,233,000	89,167,000	88,145,000	88,998,000
Income per common share - Basic (in dollars per share)	$ 0.08	$ 0.13	$ 0.19	$ 0.33
Income per common share - Diluted (in dollars per share)	$ 0.08	$ 0.13	$ 0.19	$ 0.32
Employee And Directors Stock Options [Member]
Computation of basic and diluted earnings per share
Anti-dilutive securities excluded from diluted earnings per share calculations (in shares)	2,251,303	1,249,399	2,395,158	1,375,604
Restricted Stock Units R S U [Member]
Computation of basic and diluted earnings per share
Anti-dilutive securities excluded from diluted earnings per share calculations (in shares)	2,367	178,421	79,947	106,194