Fair Value of Financial Instruments Financial Instruments Carried at Historical Costs (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value	$ 1,792,275	$ 1,858,135
Fair value	1,806,224	1,844,260
Revolving credit facility [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value	14,653	25,153
Fair value	14,769	25,222
United States term loan [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value	1,539,700	1,576,100
Fair value	1,550,939	1,562,385
Canadian term loan [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value	0	14,446
Fair value	0	14,353
Australian term loan [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value	188,461	190,100
Fair value	191,668	191,057
Amortizing notes component of TEUs [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value	29,590	32,435
Fair value	28,822	31,484
Other debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Carrying value	19,871	19,901
Fair value	$ 20,026	$ 19,759