Employee Benefit Programs (Details)	12 Months Ended																12 Months Ended
	Dec. 31, 2011 USD ($)	Dec. 31, 2010 USD ($)	Dec. 31, 2009 USD ($)	Dec. 31, 2011 GWI 401k Savings Plan [Member] USD ($)	Dec. 31, 2010 GWI 401k Savings Plan [Member] USD ($)	Dec. 31, 2009 GWI 401k Savings Plan [Member] USD ($)	Dec. 31, 2011 Canadian Retirement Benefit Plan 1 [Member]	Dec. 31, 2011 Canadian Retirement Benefit Plan 2 [Member]	Dec. 31, 2011 Canada [Member] USD ($)	Dec. 31, 2010 Canada [Member] USD ($)	Dec. 31, 2009 Canada [Member] USD ($)	Dec. 31, 2011 Australian Retirement Benefit Plan [Member] USD ($)	Dec. 31, 2010 Australian Retirement Benefit Plan [Member] USD ($)	Dec. 31, 2009 Australian Retirement Benefit Plan [Member] USD ($)	Dec. 31, 2011 Pension Plans, Defined Benefit [Member] USD ($)	Dec. 31, 2011 Defined Benefit Postretirement Health Care and Life Insurance Benefits USD ($) employees	Dec. 31, 2011 Maximum Employer Match [Member] Canadian Retirement Benefit Plan 1 [Member] USD ($)	Dec. 31, 2011 Maximum Employer Match [Member] Canadian Retirement Benefit Plan 1 [Member] CAD
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amounts awarded under performance-based bonus programs	$ 10,700,000	$ 13,700,000	$ 7,800,000
Description of defined contribution plans				.04			.05	.04				.09
Contributions to plans by employer				1,700,000	1,600,000	1,600,000			600,000	400,000	300,000	2,800,000	2,200,000	1,800,000			2,449	2,500
Defined benefit plan liability															100,000	3,600,000
Accumulated other comprehensive income/(loss), pension and other postretirement benefit plans, net of tax	$ (20,000)	$ 22,000													$ (400,000)	$ 400,000
Employees Participating In Defined Benefit Plan																24
Current employees eligible to participate in defined benefit plan																9