Annual report pursuant to Section 13 and 15(d)

Line of Credit and Short-Term Borrowings - Additional Information (Detail)

v3.3.1.900
Line of Credit and Short-Term Borrowings - Additional Information (Detail) - USD ($)
 12 Months Ended
Dec. 31, 2015
Jun. 30, 2015
Dec. 31, 2014
Line Of Credit Facility [Line Items]      
Line of credit facility, expiration period 5 years    
Line of credit facility, outstanding amount $ 100,000   $ 100,000
Credit Agreement      
Line Of Credit Facility [Line Items]      
Maximum amount of credit facility   $ 250,000,000  
Maturity date of credit agreement Jun. 30, 2020    
Line of credit facility, interest rate Borrowings bear interest at the Company’s election based on (a) LIBOR or (b) the greater of (i) the Prime Rate, (ii) the Federal Funds Rate plus 0.5% and (iii) LIBOR for a 30-day period plus 1.0%, in each case, plus an applicable margin based on the average daily principal balance of revolving loans available under the Credit Agreement.    
Unused line of credit fee 0.25%    
Debt closing and arrangement fees $ 1,100,000    
Credit Agreement | Federal Funds Rate [Member]      
Line Of Credit Facility [Line Items]      
Line of credit facility, interest rate Federal Funds Rate plus 0.5%    
Interest rate of line of credit agreement 0.50%    
Credit Agreement | LIBOR Loans [Member]      
Line Of Credit Facility [Line Items]      
Line of credit facility, interest rate LIBOR for a 30-day period plus 1.0%    
Interest rate of line of credit agreement 1.00%    
Maximum [Member]      
Line Of Credit Facility [Line Items]      
Additional amount in credit facility   $ 100,000,000