Stock Based Compensation (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009	Dec. 31, 2012
Assumptions used to estimate fair value of options granted [Abstract]
Expected dividend yield (in hundredths)	2.73%
Expected stock price volatility, minimum (in hundredths)	53.52%	48.80%	47.75%
Expected stock price volatility, maximum (in hundredths)	57.19%	53.21%	51.32%
Risk-free interest rate range, minimum (in hundredths)	1.24%	1.33%	1.79%
Risk-free interest rate range, maximum (in hundredths)	1.33%	2.84%	3.26%
Total fair value of options granted	$ 727	$ 995	$ 822
Number of Shares [Roll Forward]
Beginning Balance (in shares)	2,058	2,054	2,505
Granted (in shares)	147	126	128
Exercised (in shares)	(272)	(121)	(559)
Cancelled (in shares)	(113)	(1)	(20)
Ending Balance (in shares)	1,820	2,058	2,054	2,505
Vested at December 31, 2012 (in shares)	1,568
Exercisable at December 31, 2012 (in shares)	1,568
Weighted Average Exercise Price Per Share [Roll Forward]
Beginning Balance (in dollars per share)	$ 14.28	$ 13.77	$ 12.81
Granted (in dollars per share)	$ 12.00	$ 17.62	$ 14.18
Exercised (in dollars per share)	$ 9.39	$ 9.27	$ 9.46
Cancelled (in dollars per share)	$ 9.98	$ 8.90	$ 13.22
Ending Balance (in dollars per share)	$ 15.08	$ 14.28	$ 13.77	$ 12.81
Vested at December 31, 2012 (in dollars per share)	$ 15.24
Exercisable at December 31, 2012 (in dollars per share)	$ 15.24
Weighted Average Remaining Term [Abstract]
Weighted average remaining term, outstanding	3 years 8 months 16 days	3 years 11 months 9 days	4 years 10 months 6 days	4 years 10 months 13 days
Vested at December 31, 2012	2 years 10 months 24 days
Exercisable at December 31, 2012	2 years 10 months 24 days
Aggregate Intrinsic Value [Abstract]
Aggregate intrinsic value, outstanding	1,520	1,496	13,978	5,944
Vested at December 31, 2012	1,334
Exercisable at December 31, 2012	1,334
Weighted-average grant-date fair value of options granted (in dollars per share)	$ 4.95	$ 7.90	$ 6.67
Total intrinsic value for options exercised	988	908	3,819
Cash received from option exercises under all plans	2,681	1,073	5,288
Tax benefit from stock options exercised	244	293	1,109
Unrecognized compensation cost related to nonvested options and restricted shares outstanding	880	959	879
Weighted average period over which cost is expected to be recognized	1 year 8 months 12 days
Number of Shares [Roll Forward]
Nonvested, Beginning Balance (in shares)	261	320	386
Granted (in shares)	147	126	128
Vested (in shares)	(152)	(185)	(186)
Forfeited (in shares)	(4)		(8)
Nonvested, Ending Balance (in shares)	252	261	320	386
Weighted Average Grant Date Fair Value Per Share [Roll Forward]
Nonvested, Beginning Balance (in dollars per share)	$ 6.35	$ 4.93	$ 4.26
Granted (in dollars per share)	$ 4.95	$ 7.90	$ 6.67
Vested (in dollars per share)	$ 5.36	$ 4.95	$ 6.67
Forfeited (in dollars per share)	$ 5.60		$ 4.49
Nonvested, Ending Balance (in dollars per share)	$ 6.12	$ 6.35	$ 4.93	$ 4.26
Schedule of Share based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Abstract]
Number outstanding (in shares)					1,820
Number exercisable (in shares)	1,568
Stock based compensation expense	3,129	2,098	1,886
Amounts related to employee stock-based compensation capitalized as assets during the three years	0
6.20 - 8.26 [Member]
Schedule of Share based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Abstract]
Range of exercise price, minimum (in dollars per share)	$ 6.20
Range of exercise price, maximum (in dollars per share)	$ 8.26
Number outstanding (in shares)					168
Weighted average remaining contractual life	5 years 10 months 24 days
Weighted average exercise price (in dollars per share)	$ 6.96
Number exercisable (in shares)	168
Weighted average exercise price (in dollars per share)	$ 6.96
8.26-10.33 [Member]
Schedule of Share based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Abstract]
Range of exercise price, minimum (in dollars per share)	$ 8.26
Range of exercise price, maximum (in dollars per share)	$ 10.33
Number outstanding (in shares)					54
Weighted average remaining contractual life	2 months 12 days
Weighted average exercise price (in dollars per share)	$ 9.22
Number exercisable (in shares)	54
Weighted average exercise price (in dollars per share)	$ 9.22
10.33-12.39 [Member]
Schedule of Share based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Abstract]
Range of exercise price, minimum (in dollars per share)	$ 10.33
Range of exercise price, maximum (in dollars per share)	$ 12.39
Number outstanding (in shares)					158
Weighted average remaining contractual life	8 years 1 month 6 days
Weighted average exercise price (in dollars per share)	$ 11.70
Number exercisable (in shares)	24
Weighted average exercise price (in dollars per share)	$ 10.83
12.39-14.45 [Member]
Schedule of Share based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Abstract]
Range of exercise price, minimum (in dollars per share)	$ 12.39
Range of exercise price, maximum (in dollars per share)	$ 14.45
Number outstanding (in shares)					515
Weighted average remaining contractual life	2 years 4 months 24 days
Weighted average exercise price (in dollars per share)	$ 13.93
Number exercisable (in shares)	472
Weighted average exercise price (in dollars per share)	$ 14.01
14.45-16.52 [Member]
Schedule of Share based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Abstract]
Range of exercise price, minimum (in dollars per share)	$ 14.45
Range of exercise price, maximum (in dollars per share)	$ 16.52
Number outstanding (in shares)					179
Weighted average remaining contractual life	4 years 8 months 12 days
Weighted average exercise price (in dollars per share)	$ 15.89
Number exercisable (in shares)	175
Weighted average exercise price (in dollars per share)	$ 15.89
16.52-18.58 [Member]
Schedule of Share based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Abstract]
Range of exercise price, minimum (in dollars per share)	$ 16.52
Range of exercise price, maximum (in dollars per share)	$ 18.58
Number outstanding (in shares)					256
Weighted average remaining contractual life	4 years 4 months 24 days
Weighted average exercise price (in dollars per share)	$ 18.07
Number exercisable (in shares)	218
Weighted average exercise price (in dollars per share)	$ 18.05
18.58-20.65 [Member]
Schedule of Share based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Abstract]
Range of exercise price, minimum (in dollars per share)	$ 18.58
Range of exercise price, maximum (in dollars per share)	$ 20.65
Number outstanding (in shares)					475
Weighted average remaining contractual life	2 years 4 months 24 days
Weighted average exercise price (in dollars per share)	$ 18.89
Number exercisable (in shares)	452
Weighted average exercise price (in dollars per share)	$ 18.89
20.65-21.08 [Member]
Schedule of Share based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range [Abstract]
Range of exercise price, minimum (in dollars per share)	$ 20.65
Range of exercise price, maximum (in dollars per share)	$ 21.08
Number outstanding (in shares)					15
Weighted average remaining contractual life	6 years 9 months 18 days
Weighted average exercise price (in dollars per share)	$ 21.04
Number exercisable (in shares)	5
Weighted average exercise price (in dollars per share)	$ 21.08
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense relating to outstanding options	780	888	886
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense relating to outstanding options	2,349	1,210	1,000
Aggregate Intrinsic Value [Abstract]
Unrecognized compensation cost related to nonvested options and restricted shares outstanding	$ 1,438	$ 1,984	$ 1,316
Weighted average period over which cost is expected to be recognized	2 years
Number of Shares [Roll Forward]
Nonvested, Beginning Balance (in shares)	343	276	237
Granted (in shares)	149	126	85
Vested (in shares)	(136)	(59)	(7)
Forfeited (in shares)			(39)
Nonvested, Ending Balance (in shares)	356	343	276
Weighted Average Grant Date Fair Value Per Share [Roll Forward]
Nonvested, Beginning Balance (in dollars per share)	$ 11.86	$ 10.90	$ 10.70
Granted (in dollars per share)	$ 11.84	$ 15.86	$ 13.83
Vested (in dollars per share)	$ 6.94	$ 15.90	$ 10.39
Forfeited (in dollars per share)			$ 16.93
Nonvested, Ending Balance (in dollars per share)	$ 13.72	$ 11.86	$ 10.90
2006 Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock available for issuance (in shares)	1,255
Weighted Average Remaining Term [Abstract]
Vested at December 31, 2012	3 years
Exercisable at December 31, 2012	10 years
2006 Long-Term Incentive Plan [Member] | Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued in period (in shares)	130	111	108
2006 Long-Term Incentive Plan [Member] | Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued in period (in shares)	149	126	85
Weighted Average Remaining Term [Abstract]
Vested at December 31, 2012	3 years
2003 Equity Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock available for issuance (in shares)	5,252				5,252
Outside Directors Stock Option Plan [Member]
Weighted Average Remaining Term [Abstract]
Vested at December 31, 2012	2 years
Exercisable at December 31, 2012	10 years
Outside Directors Stock Option Plan [Member] | Stock Options [Member] | Director [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares issued in period (in shares)	17	15	15
Minimum [Member]
Assumptions used to estimate fair value of options granted [Abstract]
Expected dividend yield (in hundredths)		1.57%	0.76%
Weighted-average expected life of options	6 years 2 months 16 days	6 years 3 months 11 days	6 years 6 months 11 days
Forfeiture rate (in hundredths)	1.00%	1.00%	1.00%
Maximum [Member]
Assumptions used to estimate fair value of options granted [Abstract]
Expected dividend yield (in hundredths)		2.66%	1.24%
Weighted-average expected life of options	7 years 8 months 12 days	7 years 7 months 17 days	7 years 4 months 24 days
Forfeiture rate (in hundredths)	3.00%	3.00%	3.00%