Subsequent Event - Additional Information (Detail) - 2016 Amendment [Member] - Subsequent Event [Member]	Feb. 09, 2016 USD ($)
Subsequent Event [Line Items]
Debt Instrument, Description	(i) the issuance period for the shelf notes to be issued and sold pursuant to the Note Purchase Agreement is extended until the earlier of February 9, 2019 or the termination of the issuance and sale of the shelf notes upon the 30 days’ prior notice of either PIM or the Company, and (ii) the definition of the “Available Facility Amount,” which is the aggregate amount of the shelf notes that may be authorized for purchase pursuant to the Note Purchase Agreement was amended to equal a formula based on: $250 million, minus the aggregate principal amount of the shelf notes then outstanding and purchased pursuant to the Note Purchase Agreement, minus the shelf notes accepted by the Company for purchase, but not yet purchased, by the Purchaser pursuant to the Note Purchase Agreement; provided, however, the aggregate amount of the shelf notes purchased by any corporation or other entity controlling, controlled by, or under common control with, PIM shall not exceed $200 million.
Stated formula value for determining available facility amount	$ 250,000,000
Maximum [Member]
Subsequent Event [Line Items]
Debt instrument, face amount	$ 200,000,000