Annual report pursuant to Section 13 and 15(d)

Accumulated Other Comprehensive Income (Loss) - Summary of Changes in Accumulated Other Comprehensive Income (Loss) (Details)

v3.20.4
Accumulated Other Comprehensive Income (Loss) - Summary of Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($)
$ in Thousands
 12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning Balance $ 944,764 $ 823,116 $ 786,760
Other comprehensive income (loss) before reclassifications (196) (3,581) 3,159
Amounts reclassified out of accumulated other comprehensive income (loss) (1,358) (2,714) (233)
Other comprehensive income (loss) (1,554) (6,295) 2,926
Ending Balance 814,805 944,764 823,116
Other comprehensive income (loss) before reclassifications, tax expense 337 (836) 548
Amounts reclassified out of accumulated other comprehensive income (loss), tax expense (555) (1,108) (88)
Other comprehensive income (loss) before reclassifications, tax expense 337 (836) 548
Tax benefit associated with change in pension actuarial loss (507) (734) 726
Amounts reclassified out of accumulated other comprehensive income (loss), tax expense (555) (1,108) (88)
Gains and (Losses) on Cash Flow Hedges      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning Balance (1,326) 3,034 1,750
Other comprehensive income (loss) before reclassifications 1,140 (1,646) 1,517
Amounts reclassified out of accumulated other comprehensive income (loss) (1,358) (2,714) (233)
Other comprehensive income (loss) (218) (4,360) 1,284
Ending Balance (1,544) (1,326) 3,034
Defined Benefit Pension Plan      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning Balance (736) 1,199 (443)
Other comprehensive income (loss) before reclassifications (1,336) (1,935) 1,642
Amounts reclassified out of accumulated other comprehensive income (loss) 0 0 0
Other comprehensive income (loss) (1,336) (1,935) 1,642
Ending Balance (2,072) (736) 1,199
Accumulated Other Comprehensive Income (Loss)      
Accumulated Other Comprehensive Income (Loss) [Line Items]      
Beginning Balance (2,062) 4,233 1,307
Ending Balance $ (3,616) $ (2,062) $ 4,233