Goodwill And Other Intangible Assets (Other Intangibles) (Details) (USD $)	12 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 385,714,000	$ 338,784,000
Accumulated Amortization	(126,878,000)	(111,960,000)
Net Carrying Amount	258,836,000	226,824,000
Intangible asset residual value	0
Amortization	29,845,000	27,278,000	25,209,000
Estimated future amortization expense in 2015	29,200,000
Estimated future amortization expense in 2016	27,500,000
Estimated future amortization expense in 2017	25,700,000
Estimated future amortization expense in 2018	24,000,000
Estimated future amortization expense in 2019	22,000,000
Estimated future amortization expense thereafter	130,400,000
Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	345,199,000	294,598,000
Accumulated Amortization	(107,577,000)	(91,354,000)
Net Carrying Amount	237,622,000	203,244,000
Non-competition agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	40,316,000	42,891,000
Accumulated Amortization	(19,287,000)	(19,338,000)
Net Carrying Amount	21,029,000	23,553,000
Other intangible assets [Member]
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	199,000	1,295,000
Accumulated Amortization	(14,000)	(1,268,000)
Net Carrying Amount	185,000	27,000
Customer relationships, non-competition agreements and other [Member]
Finite-Lived Intangible Assets [Line Items]
Amortization	$ 28,600,000	$ 26,200,000
Weighted Average [Member] | Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	17 years	15 years
Weighted Average [Member] | Non-competition agreements [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years	7 years
Minimum [Member] | Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	7 years
Maximum [Member] | Customer relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Asset, Useful Life	25 years