Acquisitions - Assets Acquired and Liabilities Assumed (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Jun. 30, 2016	Feb. 01, 2016	Jun. 30, 2015
Business Acquisition [Line Items]
Goodwill	$ 2,571,297	$ 2,585,343		$ 2,189,816
NSS Acquisition
Business Acquisition [Line Items]
Cash and cash equivalents			$ 2,596
Accounts receivable			211,055
Prepaid expenses and other current assets			14,628
Property and equipment			21,320
Intangible assets			110,500
Goodwill			359,088
Other long-term assets			437
Accounts payable			(57,616)
Accrued compensation and benefits			(38,953)
Other accrued expenses and current liabilities			(38,116)
Deferred income taxes			(37,796)
Other long-term liabilities			(5,280)
Total estimated consideration			$ 541,863