Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Intangible Assets (Excluding Goodwill) [Line Items]
Definite-lived intangible assets, gross carrying amount	$ 123,302	$ 123,134
Definite-lived intangible assets, accumulated amortization	89,145	81,511
Total	34,157	41,623
Total intangible assets, gross carrying amount	147,578	158,584
Total intangible assets, accumulated amortization	97,398	89,764
Total intangible assets, net carrying amount	50,180	68,820	$ 78,181
Non-compete agreements
Intangible Assets (Excluding Goodwill) [Line Items]
Definite-lived intangible assets, gross carrying amount	864	833
Definite-lived intangible assets, accumulated amortization	864	833
Total	0	0
Customer relationships
Intangible Assets (Excluding Goodwill) [Line Items]
Definite-lived intangible assets, gross carrying amount	122,438	122,301
Definite-lived intangible assets, accumulated amortization	88,281	80,678
Total	34,157	41,623
Total intangible assets, net carrying amount	34,157	41,623	50,900
Trademarks
Intangible Assets (Excluding Goodwill) [Line Items]
Indefinite-lived intangible assets, gross carrying amount	24,276	35,450
Indefinite-lived intangible assets, accumulated amortization	8,253	8,253
Indefinite-lived intangible assets, net carrying amount	16,023	27,197
Total intangible assets, net carrying amount	$ 16,023	$ 27,197	$ 27,197