Fair Value - Presentation of Carrying Values and Fair Values of Certain Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Assets:
Investments, available-for-sale	$ 130,898	$ 131,582
Other investments	10,286	11,256
Liabilities:
Debentures payable	40,268	40,256
Term loan from principal stockholder	29,760	29,753
Carrying Value
Assets:
Investments, available-for-sale	130,898	131,582
Other investments	10,286	11,256
Liabilities:
Debentures payable	40,268	40,256
Term loan from principal stockholder	29,760	29,753
Fair Value
Assets:
Investments, available-for-sale	130,898	131,582
Other investments	10,286	11,256
Liabilities:
Debentures payable	19,346	20,275
Term loan from principal stockholder	$ 28,673	$ 28,504