Debt and Credit Facility Credit Facility (Details)		1 Months Ended	3 Months Ended		9 Months Ended
		Feb. 28, 2017 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jun. 30, 2017 USD ($) tranche	Mar. 31, 2017 USD ($)
Line of Credit Facility [Line Items]
Interest coverage ratio			3.50		3.50
Repayments of lines of credit	[1]				$ 187,000,000	$ 1,078,500,000
Debt issuance costs		$ 33,700,000	$ 41,900,000		$ 41,900,000			$ 46,800,000
Credit Facility								$ 0
Debt instrument, description of variable rate basis					the highest of JPMorgan Chase Bank, N.A.'s prime rate, the federal funds rate plus a margin equal to 0.50% and the adjusted LIBOR rate for a 1-month interest period plus a margin equal to 1.00%
Interest expense			$ 49,744,000	$ 35,143,000	$ 148,693,000	104,685,000
Revolving credit facility
Line of Credit Facility [Line Items]
Credit agreement maximum borrowing amount							$ 2,774,000,000.000
Number of commitment tranches | tranche							2
Credit agreement, total leverage ratio, maximum			5.00		5.00			5.00
Credit Agreement, total consolidated debt, maximum			$ 700,000,000		$ 700,000,000
Credit agreement, total leverage ratio, temporary maximum allowed, first four quarters			5.50		5.50
Credit agreement, total leverage ratio, temporary maximum allowed, next three quarters			5.25		5.25
Credit agreement, senior leverage ratio, maximum			3.50		3.50
Credit agreement, senior leverage ratio, minimum to obtain additional funding			2.50		2.50
Repayments of lines of credit		1,682,500,000
Debt issuance costs		$ 2,100,000
Credit Facility			$ 0		$ 0
Period for leverage ratio to determine interest rate spread					preceding four fiscal quarters
Interest expense			$ 2,300,000	$ 11,900,000	$ 7,300,000	$ 35,500,000
Interest rate spread on overdue principal in event of default (percentage)			2.00%		2.00%
Interest rate spread on overdue amounts in event of default (percentage)			2.00%		2.00%
Revolving credit facility | 2020 Tranche
Line of Credit Facility [Line Items]
Credit agreement maximum borrowing amount			$ 3,122,300,000.0		$ 3,122,300,000.0
Revolving credit facility | Debt instrument interest rate option 2
Line of Credit Facility [Line Items]
Debt instrument, description of variable rate basis					adjusted LIBOR rate (based on one, two, three, or six-month interest periods)
Foreign line of credit
Line of Credit Facility [Line Items]
Credit agreement maximum borrowing amount			125,000,000		$ 125,000,000
Standby letters of credit
Line of Credit Facility [Line Items]
Credit agreement maximum borrowing amount			25,000,000		25,000,000
Line of credit facility swingline loan sublimit
Line of Credit Facility [Line Items]
Credit agreement maximum borrowing amount			$ 25,000,000		$ 25,000,000
Minimum | Revolving credit facility | Debt instrument interest rate option 1
Line of Credit Facility [Line Items]
Spread on variable rate (percentage)					0.25%
Maximum | Revolving credit facility | Debt instrument interest rate option 1
Line of Credit Facility [Line Items]
Spread on variable rate (percentage)					1.25%
Maximum | Revolving credit facility | Debt instrument interest rate option 2
Line of Credit Facility [Line Items]
Spread on variable rate (percentage)					2.25%

[1] During the nine months ended December 31, 2017, the Company issued $111.3 million principal amount of 2017 Junior Notes and 3.2 million shares of common stock in exchange for $111.3 million principal amount of 2007 Junior Notes. Refer to Note 13 Debt and Credit Facility for further discussion.