Annual report pursuant to Section 13 and 15(d)

Long-term Debt - Additional Information (Details)

v3.20.4
Long-term Debt - Additional Information (Details) - USD ($)
12 Months Ended
May 04, 2023
May 04, 2020
Dec. 31, 2020
Dec. 31, 2019
Debt Instrument [Line Items]        
Senior note     $ 99,931,000 $ 45,000,000
Debt instrument, due date     Jan. 03, 2021  
Fixed interest rate     4.79%  
Proceeds from issuance of senior promissory notes     $ 99,923,000  
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage     0.10%  
Letter of Credit Fee in Percentage     1.00%  
Letters of Credit Outstanding, Amount     $ 42,100,000 48,900,000
Series B [Member] | Forecast [Member]        
Debt Instrument [Line Items]        
Scheduled principal payment $ 20,000,000.0      
Debt instrument, due date May 04, 2027      
Notes interest 3.10%      
Maturity Date Description The Series B Notes bear interest at 3.10% per annum and mature on May 4, 2027, unless prepaid.      
P G I M I N C [Member] | Series B Notes [Member]        
Debt Instrument [Line Items]        
Proceeds from issuance of senior promissory notes   $ 100,000,000.0    
Minimum [Member]        
Debt Instrument [Line Items]        
Interest Rate Spread added to Rate     0.00%  
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage     0.10%  
Maximum [Member]        
Debt Instrument [Line Items]        
Interest Rate Spread added to Rate     0.375%  
Line of Credit Facility, Unused Capacity, Commitment Fee Percentage     0.175%  
London Interbank Offered Rate (LIBOR) [Member] | Minimum [Member]        
Debt Instrument [Line Items]        
Interest Rate Spread added to Rate     1.00%  
London Interbank Offered Rate (LIBOR) [Member] | Maximum [Member]        
Debt Instrument [Line Items]        
Interest Rate Spread added to Rate     1.375%  
2019 Credit Agreement [Member]        
Debt Instrument [Line Items]        
Original borrowing capacity     $ 250,000,000.0  
Line of Credit Facility Accordion     150,000,000.0  
Line of Credit Facility, Maximum Borrowing Capacity     400,000,000.0  
Letter of Credit [Member]        
Debt Instrument [Line Items]        
Line of Credit Facility, Capacity Available for Specific Purpose Other than for Trade Purchases     100,000,000.0  
Prior Credit Agreement [Member]        
Debt Instrument [Line Items]        
Line of Credit Facility, Maximum Borrowing Capacity     300,000,000.0  
Unsecured Senior Notes [Member]        
Debt Instrument [Line Items]        
Senior note       $ 45,000,000.0
Unsecured Senior Note Due January 3, 2021 [Member]        
Debt Instrument [Line Items]        
Scheduled principal payment     $ 45,000,000.0  
Note Agreement [Member] | Maximum [Member] | P G I M I N C [Member]        
Debt Instrument [Line Items]        
Aggregate amount on promissory notes issued   $ 350,000,000.0