Stock-Based Compensation (Restricted Shares) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	3,680	3,200
Share-based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition	2 years 1 month 6 days
Share-based Payment Arrangement, Expense	$ 1,565,000	$ 1,360,000
Weighted - Average Grant Date Fair Value (in dollars per share)
Maximum Aggregate Value of Performance Unit Award Outstanding	$ 1,300,000
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	9,395
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense	$ (12,000)	39,000
Weighted - Average Grant Date Fair Value (in dollars per share)
Shares Issued, Price Per Share	$ 29.26
Restricted Shares
Weighted - Average Grant Date Fair Value (in dollars per share)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Aggregate Intrinsic Value, Vested	$ 2,000,000.0	1,100,000
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Expense	$ 1,380,000	1,153,000
Time-Based Vesting | Restricted Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	0
Number of Shares (in shares)
Outstanding at January 1	32,230
Released	4,000
Forfeited	200
43921	28,030
Weighted - Average Grant Date Fair Value (in dollars per share)
Outstanding at January 1	$ 33.05
Awarded	0
Released	31.63
Forfeited	34.14
43921	$ 33.25
Performance-Based Vesting | Restricted Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period	80,338
Number of Shares (in shares)
Outstanding at January 1	253,884
Awarded	80,338
Released	56,827
Forfeited	3,402
43921	273,993
Weighted - Average Grant Date Fair Value (in dollars per share)
Outstanding at January 1	$ 33.29
Awarded	32.91
Released	32.42
Forfeited	33.04
43921	$ 33.36
Treasury Stock | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	$ 275,000
Treasury Stock | Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	$ 120,000	$ 102,000