Debt (Narrative - Senior Credit Facilities) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
Line of Credit Facility [Abstract]
Loss on extinguishment of debt	$ 1.4	$ 0.0	$ 1.4	$ 0.0
Revolving Credit Facility
Line of Credit Facility [Abstract]
Revolving credit facility, maximum borrowing capacity	1,500.0		1,500.0
Revolving credit facility, available amount	$ 1,500.0		$ 1,500.0
Number of possible increases in margin			2
Effective interest rate	3.51%		3.51%
Change in control, trigger percentage	50.00%		50.00%
Letter of Credit
Line of Credit Facility [Abstract]
Letters of credit outstanding, amount	$ 0.0		$ 0.0
Minimum | Revolving Credit Facility
Line of Credit Facility [Abstract]
Revolving credit facility, commitment fee annual percentage			0.25%
Maximum | Revolving Credit Facility
Line of Credit Facility [Abstract]
Revolving credit facility, commitment fee annual percentage			0.375%
Base Rate | Revolving Credit Facility
Line of Credit Facility [Abstract]
Basis spread on variable interest rate			0.75%
LIBOR | Revolving Credit Facility
Line of Credit Facility [Abstract]
Basis spread on variable interest rate			1.75%
Potential increases in interest rate upon certain increases to leverage ratios, total			0.50%
Potential increase in interest rate upon certain increases to leverage ratios, per increase			0.25%
LIBOR | Minimum | Revolving Credit Facility
Line of Credit Facility [Abstract]
Coupon rate	0.00%		0.00%
Term Loan A Facility | Term Loan
Line of Credit Facility [Abstract]
Number of possible increases in margin			2
Effective interest rate	3.51%		3.51%
Quarterly principal payment percent	1.25%		1.25%
Quarterly principal payment percent, year two	1.75%		1.75%
Quarterly principal payment percent, year three	2.50%		2.50%
Quarterly principal payment percent, year four	2.50%		2.50%
Term Loan A Facility | Base Rate | Term Loan
Line of Credit Facility [Abstract]
Basis spread on variable interest rate			0.75%
Term Loan A Facility | LIBOR | Term Loan
Line of Credit Facility [Abstract]
Basis spread on variable interest rate			1.75%
Potential increases in interest rate upon certain increases to leverage ratios, total			0.50%
Potential increase in interest rate upon certain increases to leverage ratios, per increase			0.25%
Term Loan A Facility | LIBOR | Minimum | Term Loan
Line of Credit Facility [Abstract]
Coupon rate	0.00%		0.00%
Term Loan B Facility | Term Loan
Line of Credit Facility [Abstract]
Effective interest rate	4.01%		4.01%
Quarterly principal payment percent	0.25%		0.25%
Early repayments, principal amount	$ 101.9		$ 101.9
Term Loan B Facility | Base Rate | Term Loan
Line of Credit Facility [Abstract]
Basis spread on variable interest rate			1.25%
Term Loan B Facility | LIBOR | Term Loan
Line of Credit Facility [Abstract]
Basis spread on variable interest rate			2.25%
Term Loan B Facility | LIBOR | Minimum | Term Loan
Line of Credit Facility [Abstract]
Coupon rate	0.00%		0.00%