Variable Interest Entity - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Variable Interest Entity [Line Items]
Earnings (loss) in equity of unconsolidated affiliate	$ 200,000	$ (300,000)
Trade receivables	2,000,000
Other assets	200,000	0
Operating revenue	$ 2,600,000	0	$ 3,400,000
PHIC's date of incorporation	May 26, 2011
Loan receivables	$ 1.2
PHI Century Limited [Member]
Variable Interest Entity [Line Items]
Investment in the common stock	49.00%
Allowance for Trade Receivables [Member]
Variable Interest Entity [Line Items]
Allowance for bad debts against trade receivables		$ 1,500,000