Stock-Based Compensation (Additional Information For RSU's Under The 2007 Plan) (Details) - 2007 and 2012 Incentive plan - Restricted stock units (RSUs) - shares	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Number of Shares [Roll Forward]
RSUs outstanding, beginning balance (in shares)	750,000	725,000	733,000
Granted (in shares)	187,000	248,000	189,000
Released (in shares)	(226,000)	(212,000)	(189,000)
Forfeited (in shares)	(16,000)	(11,000)	(8,000)
RSUs outstanding, ending balance (in shares)	695,000	750,000	725,000
Expected to vest (in shares)	682,000	731,000	691,000