Intangible Assets (Details) (USD $) In Thousands, unless otherwise specified	Sep. 29, 2012	Mar. 31, 2012
Intangible Assets (Excluding Goodwill) [Line Items]
Definite-lived intangible assets, gross carrying amount	$ 173,723	$ 173,735
Definite-lived intangible assets, accumulated amortization	81,862	74,933
Definite-llved intangible assets, net carrying amount	91,861	98,802
Total intangible assets, gross carrying amount	209,715	209,727
Total intangible assets, accumulated amortization	90,115	83,186
Total intangible assets, net carrying amount	119,600	126,541	[1]
Non-compete agreements [Member]
Intangible Assets (Excluding Goodwill) [Line Items]
Definite-lived intangible assets, gross carrying amount	12,216	12,228
Definite-lived intangible assets, accumulated amortization	10,563	10,194
Definite-llved intangible assets, net carrying amount	1,653	2,034
Customer relationships [Member]
Intangible Assets (Excluding Goodwill) [Line Items]
Definite-lived intangible assets, gross carrying amount	140,669	140,669
Definite-lived intangible assets, accumulated amortization	53,368	47,226
Definite-llved intangible assets, net carrying amount	87,301	93,443
Total intangible assets, net carrying amount	87,301	93,443
Acquired backlog [Member]
Intangible Assets (Excluding Goodwill) [Line Items]
Definite-lived intangible assets, gross carrying amount	20,838	20,838
Definite-lived intangible assets, accumulated amortization	17,931	17,513
Definite-llved intangible assets, net carrying amount	2,907	3,325
Trademarks [Member]
Intangible Assets (Excluding Goodwill) [Line Items]
Indefinite-lived intangible assets, gross carrying amount	35,992	35,992
Indefinite-lived intangible assets, accumulated amortization	8,253	8,253
Indefinite-lived intangible assets, net carrying amount	27,739	27,739
Total intangible assets, net carrying amount	$ 27,739	$ 27,739

[1] Derived from audited financial statements