Subsequent Events - Additional Information (Detail) - Khazanah Nasional Berhad and Mitsui and Co., LTD - Asia-Pacific dialysis business - Subsequent Event $ in Thousands	Aug. 01, 2016 USD ($)
Subsequent Event [Line Items]
Subscribed investment amount	$ 300,000
Ownership interest percentage	40.00%
Investment period	3 years
Initial investment in equity method investment	$ 50,000

Percentage of voting equity interests acquired at the acquisition date in the business combination.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=65885119&loc=d3e1392-128463

Name:	us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant