Shareholders' Equity - Additional Information (Detail)			1 Months Ended	6 Months Ended
Shareholders' Equity - Additional Information (Detail)	Mar. 09, 2017 $ / shares shares	Sep. 30, 2016	Mar. 31, 2017 Stockholder	Jun. 30, 2017
Class Of Stock [Line Items]
Reverse stock split ratio		0.10
Description of reverse stock split				On September 30, 2016, the Company underwent a reverse stock split at a ratio of 1-for-10 (the “2016 Reverse Split”).
Common stock
Class Of Stock [Line Items]
Reverse stock split ratio			0.01
Effective date of reverse stock split				fourth quarter of 2017
Description of reverse stock split				In March 2017, the Board of Directors (the "Board") of the Company approved and recommended that the Company’s shareholders approve a 1-for-100 reverse stock split of the Company’s shares of Class A Stock and Class B common stock (collectively, the “Common Stock”), to be effective no earlier than the fourth quarter of 2017 (the "2017 Reverse Split"), to enable the Company to (i) terminate the registration of the Class A Stock under the Securities Exchange Act of 1934, as amended (the “Exchange Act”); (ii) cease to be a reporting company under the Exchange Act; and (iii) terminate its Nasdaq listing if, after the 2017 Reverse Split, there are fewer than 300 record holders of Class A Stock. At the Company’s annual meeting of shareholders on June 14, 2017, the Company’s shareholders approved the 2017 Reverse Split and authorized the Board to implement the 2017 Reverse Split in the fourth quarter of 2017. The Board may abandon the proposed 2017 Reverse Split at any time if the Board determines that the 2017 Reverse Split will not facilitate de-registration and de-listing of the Common Stock or is no longer in the best interests of the Company or its shareholders. If implemented, the 2017 Reverse Split will reduce all issued and outstanding shares of Common Stock into one hundredth (1/100) of the pre-split number of shares of Common Stock. In lieu of fractional shares that would otherwise result from the 2017 Reverse Split, the Company will pay each holder cash.
Reduction of number of common stock after reverse split			0.01
Class A Stock \| Maximum
Class Of Stock [Line Items]
Number of record holders of Class A Stock after Reverse Split \| Stockholder			300
Class A Stock \| Crusader
Class Of Stock [Line Items]
Number of common stock redeemed \| shares	2,432,923
Common stock, redemption price per share \| $ / shares	$ 6.55

Pendrell Corp 10-Q