Goodwill And Other Intangible Assets (Changes In Goodwill) (Details) $ in Thousands	6 Months Ended
	Sep. 30, 2015 USD ($)
Goodwill [Roll Forward]
Balance at March 31, 2015	$ 1,313,644
Acquisitions	45,537	[1]
Other adjustments, including foreign currency translation	1,850
Balance at September 30, 2015	1,361,031
Distribution Business Segment [Member]
Goodwill [Roll Forward]
Balance at March 31, 2015	1,116,569
Acquisitions	23,732	[1]
Other adjustments, including foreign currency translation	1,899
Balance at September 30, 2015	1,142,200
All Other Operations Business Segment [Member]
Goodwill [Roll Forward]
Balance at March 31, 2015	197,075
Acquisitions	21,805	[1]
Other adjustments, including foreign currency translation	(49)
Balance at September 30, 2015	$ 218,831

[1] Includes acquisitions completed during the current year and adjustments made to prior year acquisitions.