Benefit Plans - Restricted Stock Awards and Restricted Stock Units (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Weighted Average Grant-Date Fair Value Per Share
Compensation expense	$ 132	$ 571	$ 927
Restricted Stock
Shares
Unvested at the beginning of the year (in shares)	636,077
Granted (in shares)	423,823
Vested (in shares)	(287,754)
Forfeited (in shares)	(32,213)
Unvested at the end of the year (in shares)	739,933	636,077
Weighted Average Grant-Date Fair Value Per Share
Unvested at the beginning of the year (in dollars per share)	$ 35.98
Granted (in dollars per share)	29.92
Vested (in dollars per share)	29.43
Forfeited (in dollars per share)	34.76
Unvested at the end of the year (in dollars per share)	$ 35.11	$ 35.98
Compensation expense	$ 10,400	$ 8,500	$ 5,000
Grant date fair value	12,700
Unrecognized compensation expense	$ 14,200
Weighted-average period of recognition	1 year 9 months 21 days

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

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The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period.

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Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options.

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Value, after forfeiture, of shares granted under share-based payment arrangement. Excludes employee stock ownership plan (ESOP).

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