Fair Value - Presentation of Carrying Values and Fair Values of Certain Financial Instruments (Detail) - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Assets:
Investments, available-for-sale	$ 129,088	$ 131,582
Other investments	10,322	11,256
Liabilities:
Debentures payable	40,279	40,256
Term loan from principal stockholder	29,766	29,753
Carrying Value
Assets:
Investments, available-for-sale	129,088	131,582
Other investments	10,322	11,256
Liabilities:
Debentures payable	40,279	40,256
Term loan from principal stockholder	29,766	29,753
Fair Value
Assets:
Investments, available-for-sale	129,088	131,582
Other investments	10,322	11,256
Liabilities:
Debentures payable	15,381	20,275
Term loan from principal stockholder	$ 22,698	$ 28,504