Quarterly report pursuant to Section 13 or 15(d)

Recent Transactions - Pending Transactions -Additional Information (Detail)

v3.19.1
Recent Transactions - Pending Transactions -Additional Information (Detail) - USD ($)
$ in Millions
Mar. 19, 2019
Mar. 01, 2017
Mar. 31, 2019
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]      
Business combination, liabilities arising from contingencies, amount recognized   $ 0.5  
Term of time brokerage agreement   24 months  
Wspz Am Tower Site [Member]      
Summary of Investments, Other than Investments in Related Parties, Reportable Data [Line Items]      
Business Combination, Consideration Transferred $ 0.8    
Business Gross Estimated Gain Loss On Sale assets     $ 3.8