Incentive Plan (Narrative) (Details) (USD $) In Millions, except Share data	6 Months Ended
	Jun. 30, 2011	Jun. 30, 2011 2004 Incentive Award Plan [Member]	May 02, 2007 Amended And Restated 2004 Incentive Award Plan [Member]
Shares authorized and reserved for issuance under the "Incentive Plan"		4,474,102	9,474,102
Increase in number of shares reserved for issuance			5,000,000
Maximum number of shares granted per employee	1,500,000
Maximum amount of cash paid per employee	$ 10.0
Number of shares remaining for issuance under the "Incentive Plan"	3,739,090