Debt (Amended Credit Agreement) (Details)	Sep. 09, 2016 AUD	May 19, 2016 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2016 AUD	May 19, 2016 AUD	May 18, 2016 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2015 AUD
Debt Instrument [Line Items]
Term loan			$ 289,500,000				$ 292,500,000
Revolver			515,000,000				$ 485,000,000
Long-term debt			2,459,340,000
Additional increase in borrowing capacity ability			$ 450,000,000
Weighted average interest rates on outstanding borrowings			3.10%	3.10%
Revolver
Debt Instrument [Line Items]
Revolver			$ 515,000,000
Additional Revolver
Debt Instrument [Line Items]
Borrowing capacity remaining			331,400,000
Line of Credit
Debt Instrument [Line Items]
Long-term debt			1,153,031,000
Revolving Credit Facility | Line of Credit | Amended Credit Agreement [Member]
Debt Instrument [Line Items]
Increase in maximum borrowing capacity		$ 200,000,000
Maximum borrowing capacity		$ 900,000,000
Total leverage ratio		2.50			2.50
Covenant, total leverage ratio, maximum		6.25			6.25
Senior secured leverage ratio		3.50			3.50
Interest coverage ratio		3.00			3.00
Revolving Credit Facility | Line of Credit | Amended Credit Agreement [Member] | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		2.25%			2.25%
Variable rate, floor		0.00%			0.00%
Term Loan
Debt Instrument [Line Items]
Term loan			289,500,000
Term Loan | Line of Credit | Amended Credit Agreement [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 291,000,000
Term Loan | Line of Credit | Amended Credit Agreement [Member] | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate		2.50%			2.50%
Variable rate, floor		0.75%			0.75%
Letter of credit
Debt Instrument [Line Items]
Long-term debt			53,600,000
Letter of credit | Australian LC Facility
Debt Instrument [Line Items]
Long-term debt | AUD								AUD 215,000,000
Letter of credit | Line of Credit | Amended Credit Agreement [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 300,000,000			AUD 225,000,000	$ 175,000,000
Reduction in maximum borrowing capacity | AUD	AUD 110,000,000
Letter of credit | Line of Credit | Bank Guarantee And Standby Sub Facility
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 72,100,000.0	AUD 100,000,000
Accordion | Line of Credit | Amended Credit Agreement [Member]
Debt Instrument [Line Items]
Accordion feature, increase limit		450,000,000
Multicurrency Subfacility Commitment | Line of Credit | Amended Credit Agreement [Member]
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 100,000,000