Financial Instruments and Fair Value Disclosures - Additional Information (Detail)	3 Months Ended	12 Months Ended
	Dec. 31, 2013 USD ($)	Dec. 31, 2015 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2013 USD ($) Customer
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Bad debt expense				$ 22,513,000
Receivables written off			$ 21,148,000	$ 509,000
Transfers between fair value levels		$ 0	0
Measurement period for determining fair value of debt instruments		10 days
Level 1 [Member] | Cash Held in Money Market Funds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments		$ 85,200,000	197,500,000
Level 1 [Member] | Time Deposits [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of investments		20,400,000	20,300,000
Niko [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash received pursuant to Settlement Agreement	$ 25,000,000		20,300,000
Anticipated future payments pursuant to Settlement Agreement		$ 34,800,000
Ogx and Niko Resources [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Number of customers | Customer				2
Bad debt expense				$ 22,500,000
OGX Petroleo e Gas Ltda. [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Receivables written off			$ 21,200,000