Supplemental Cash Flow Information Supplemental Cash Flow Information (Noncash Investing Activities) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Mar. 31, 2014 FY14 Acquisitions [Member]	Mar. 31, 2013 FY13 Acquisitions [Member]	Mar. 31, 2012 FY12 Acquisitions [Member]
Noncash or Part Noncash Acquisitions [Line Items]
Fair value of assets acquired	$ 218,413	$ 115,402	$ 184,017
Net cash paid for acquisitions	(205,370)	(97,521)	(160,115)
Liabilities assumed	$ 13,043	$ 17,881	$ 23,902