Supplemental Cash Flow Information (Noncash Investing and Financing Activities) (Details) - USD ($) $ in Thousands		9 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Noncash or Part Noncash Acquisitions [Line Items]
Net cash paid for acquisitions		$ (100,329)	$ (45,165)
Series of Individually Immaterial Business Acquisitions [Member]
Noncash or Part Noncash Acquisitions [Line Items]
Fair value of assets acquired		119,488	59,938
Net cash paid for acquisitions	[1]	(100,656)	(45,165)
Stock issued for acquisition	[2]	0	(4,458)
Liabilities assumed		$ 18,832	$ 10,315

[1] Includes cash paid, net of cash acquired, for current year acquisitions as well as payments for the settlement of holdback liabilities and contingent consideration arrangements associated with prior year acquisitions.

[2] Represents shares of Airgas, Inc. common stock issued in connection with a single prior year acquisition.