Accounting for Stock-based Compensation - Schedule of Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Recognized	$ 26,031	$ 19,581	$ 17,544
Stock-Based Compensation Unrecognized	$ 30,273
Employee Stock Option
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Recognized			164
Stock-Based Compensation Unrecognized Weighted- Average Period to Recognize (Year)	0 years
Restricted Stock Units (RSUs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Recognized	$ 10,644	7,410	7,080
Stock-Based Compensation Unrecognized	$ 15,345
Stock-Based Compensation Unrecognized Weighted- Average Period to Recognize (Year)	1 year 7 months 6 days
Cash Settled RSUs
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Recognized	$ 10,213	8,214	7,253
Stock-Based Compensation Unrecognized	$ 10,400
Stock-Based Compensation Unrecognized Weighted- Average Period to Recognize (Year)	1 year 8 months 12 days
Non-Employee Director Awards
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Recognized	$ 719	764	671
Stock-Based Compensation Unrecognized	$ 328
Stock-Based Compensation Unrecognized Weighted- Average Period to Recognize (Year)	4 months 24 days
Performance Shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Stock-Based Compensation Recognized	$ 4,455	$ 3,193	$ 2,376
Stock-Based Compensation Unrecognized	$ 4,200
Stock-Based Compensation Unrecognized Weighted- Average Period to Recognize (Year)	1 year 6 months

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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