Acquisitions - Estimated Values of Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014	Nov. 01, 2014
Assets acquired:
Goodwill	$ 421,760	$ 423,276
Medical Action Industries, Inc. and ArcRoyal
Assets acquired:
Current assets			$ 90,755
Property and equipment			32,814
Goodwill			151,265
Intangible assets			77,623
Total assets			352,457
Liabilities assumed:
Current liabilities			64,422
Noncurrent liabilities			26,426
Total liabilities			90,848
Fair value of net assets acquired, net of cash			261,609
Preliminary Fair Value Estimated as of Acquisition Date | Medical Action Industries, Inc. and ArcRoyal
Assets acquired:
Current assets			90,608
Property and equipment			34,048
Goodwill			150,492
Intangible assets			77,623
Total assets			352,771
Liabilities assumed:
Current liabilities			64,736
Noncurrent liabilities			26,426
Total liabilities			91,162
Fair value of net assets acquired, net of cash			261,609
Differences Between Prior and Current Period Preliminary Fair Value Estimate | Medical Action Industries, Inc. and ArcRoyal
Assets acquired:
Current assets			147
Property and equipment			(1,234)
Goodwill			773
Intangible assets			0
Total assets			(314)
Liabilities assumed:
Current liabilities			(314)
Noncurrent liabilities			0
Total liabilities			(314)
Fair value of net assets acquired, net of cash			$ 0