Benefit Plans - Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	$ 278,420	$ 260,651	$ 236,621
Qualified Plan
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percent of total investments	100.00%	100.00%
Fair value of plan assets	$ 277,637	$ 260,028
Qualified Plan | Mutual funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percent of total investments	28.00%	18.00%
Fair value of plan assets	$ 79,462	$ 48,041
Qualified Plan | Corporate bonds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percent of total investments	23.00%	20.00%
Fair value of plan assets	$ 64,715	$ 51,410
Qualified Plan | U.S. Treasury securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percent of total investments	22.00%	20.00%
Fair value of plan assets	$ 59,931	$ 52,549
Qualified Plan | Equity securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percent of total investments	21.00%	37.00%
Fair value of plan assets	$ 57,987	$ 94,434
Qualified Plan | U.S. government agency securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percent of total investments	4.00%	3.00%
Fair value of plan assets	$ 10,590	$ 8,174
Qualified Plan | Cash and money market funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Percent of total investments	2.00%	2.00%
Fair value of plan assets	$ 4,952	$ 5,420
Qualified Plan | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	202,332	200,444
Qualified Plan | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mutual funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	79,462	48,041
Qualified Plan | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate bonds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Treasury securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	59,931	52,549
Qualified Plan | Quoted Prices in Active Markets for Identical Assets (Level 1) | Equity securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	57,987	94,434
Qualified Plan | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. government agency securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Quoted Prices in Active Markets for Identical Assets (Level 1) | Cash and money market funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	4,952	5,420
Qualified Plan | Significant Other Observable  Inputs (Level 2)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	75,305	59,584
Qualified Plan | Significant Other Observable  Inputs (Level 2) | Mutual funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Significant Other Observable  Inputs (Level 2) | Corporate bonds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	64,715	51,410
Qualified Plan | Significant Other Observable  Inputs (Level 2) | U.S. Treasury securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Significant Other Observable  Inputs (Level 2) | Equity securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Significant Other Observable  Inputs (Level 2) | U.S. government agency securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	10,590	8,174
Qualified Plan | Significant Other Observable  Inputs (Level 2) | Cash and money market funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Significant Unobservable Inputs (Level 3)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Significant Unobservable Inputs (Level 3) | Mutual funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Significant Unobservable Inputs (Level 3) | Corporate bonds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Significant Unobservable Inputs (Level 3) | U.S. Treasury securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Significant Unobservable Inputs (Level 3) | Equity securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Significant Unobservable Inputs (Level 3) | U.S. government agency securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	0	0
Qualified Plan | Significant Unobservable Inputs (Level 3) | Cash and money market funds
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Fair value of plan assets	$ 0	$ 0