Stock-Based Compensation - Narrative (Details) - USD ($)	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized	$ 6,528,000
Stock-based compensation expense	5,541,000	$ 4,330,000	$ 3,355,000
Allocated share-based compensation expense	5,541,000	4,330,000	5,782,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated share-based compensation expense	$ 0	$ 0	$ 0
2015 Incentive Award Plan \| 2015 Incentive Award Plan approved on June 19, 2015 \| Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (shares)	30,000,000
Number of shares available for grant (shares)	21,213,679

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

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