Fair Value Disclosures - Schedule of Roll-forward of Fair Value of Level 3 Instruments (Detail) - Jun. 30, 2015 - Level 3 [Member] - USD ($) $ in Thousands	Total	Total
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Balance at beginning of period	$ 110,000	$ 106,000
Amounts acquired or issued	0	0
Net change in fair value	1,013	5,013
Settlements	0	0
Transfers in and/or out of Level 3	0	0
Balance at end of period	$ 111,013	$ 111,013