Incentive Plan (Narrative) (Details) - USD ($)	May. 02, 2007	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum number of shares granted per employee	1,500,000
Maximum amount of cash paid per employee	$ 10,000,000.0
Number of shares remaining for issuance under the "Incentive Plan"		4,737,954
2004 Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized and reserved for issuance under the Incentive Plan		4,474,102
Amended And Restated 2004 Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized and reserved for issuance under the Incentive Plan	9,474,102
Increase in number of shares reserved for issuance	5,000,000