Earnings per Share (Details 2) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Computation of basic and diluted earnings per share
Net income	$ 6,038	$ 10,420	$ 9,391	$ 17,396
Net weighted average common shares outstanding, basic (in shares)	87,691,000	87,674,000	87,564,000	87,408,000
Weighted average common shares outstanding, diluted (in shares)	88,092,000	89,023,000	88,033,000	88,919,000
Income per common share - Basic (in dollars per share)	$ 0.07	$ 0.12	$ 0.11	$ 0.20
Income per common share - Diluted (in dollars per share)	$ 0.07	$ 0.12	$ 0.11	$ 0.20
Employee And Directors Stock Options [Member]
Anti-dilutive securities
Anti-dilutive securities excluded from diluted earnings per share calculations (in shares)	2,562,229	1,413,369	2,443,375	1,375,346
Restricted Stock Units R S U [Member]
Anti-dilutive securities
Anti-dilutive securities excluded from diluted earnings per share calculations (in shares)	189,278	9,085	52,171	102,847