Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation expense recognized		$ 6,108	$ 4,817	$ 4,394
Unrecognized Compensation Cost		$ 3,096
Expiration date of 2007 Stock Incentive Plan		May 20, 2024
Outstanding:
Stock options exercised (in shares)				77,334
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation expense recognized		$ 5,931	$ 4,603	$ 4,231
Unrecognized Compensation Cost		$ 3,096
Weighted Average Remaining Amortization Periods		9 months 18 days
Number of units [Abstract]
Balance (in shares)		904,000	986,000	1,004,000
Granted (in shares)		314,000	252,000	304,000
Vested (in shares)	[1]	(361,000)	(334,000)	(322,000)
Cancelled or forfeited (in shares)		(15,000)	0	0
Balance (in shares)		842,000	904,000	986,000
Expected to vest (in shares)		842,000	904,000	986,000
Weighted Average Grant-date Fair Value per Unit [Abstract]
Beginning balance, Weighted average grant-date fair value (in dollars per share)		$ 14.77	$ 13.34	$ 12.74
Granted, Weighted average grant-date fair value (in dollars per share)		19.85	18.90	15.52
Vested, Weighted average grant-date fair value (in dollars per share)	[1]	11.70	13.67	13.54
Cancelled or forfeited, Weighted average grant date fair value (in dollars per share)		17.71	0	0
Ending balance, Weighted average grant-date fair value (in dollars per share)		$ 17.93	$ 14.77	$ 13.34
Phantom Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Stock-based compensation expense recognized		$ 177	$ 214	$ 163
Unrecognized Compensation Cost		$ 0
Weighted Average Remaining Amortization Periods		0 years
Number of units [Abstract]
Balance (in shares)		170,000	157,000	145,000
Granted (in shares)		10,000	10,000	10,000
Dividend equivalents issued (in shares)		3,000	3,000	2,000
Balance (in shares)		183,000	170,000	157,000
Weighted Average Grant-date Fair Value per Unit [Abstract]
Granted, Weighted average grant-date fair value (in dollars per share)		$ 17.72	$ 21.35	$ 16.25
Performance Vested Restricted Stock Units [Member] | Scheduled to Vest January 1, 2020 [Member]
Number of units [Abstract]
Balance (in shares)	[2]	167,000
Expected to vest (in shares)	[2]	167,000
Not expected to vest (in shares)	[2]	0
Performance Vested Restricted Stock Units [Member] | Scheduled to Vest January 1, 2021 [Member]
Number of units [Abstract]
Balance (in shares)		141,000
Expected to vest (in shares)		141,000
Not expected to vest (in shares)		0
Performance Vested Restricted Stock Units [Member] | Scheduled to Vest January 1, 2022 [Member]
Number of units [Abstract]
Balance (in shares)		174,000
Expected to vest (in shares)		174,000
Not expected to vest (in shares)		0
2007 Stock Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award
Maximum number of shares authorized under restricted stock, unrestricted stock, RSU's and stock options to officers, employees and non-employee directors (in shares)		6,500,000
Exercisable (in shares)
Available for future grants (in shares)		2,580,000

[1] The number of RSUs vested includes shares that the Company withheld on behalf of employees to satisfy statutory tax withholding requirements.

[2] The performance vesting criteria for the performance-based RSUs with a vesting date of January 1, 2020 were achieved.