Stock Options (Narrative) (Details) (USD $) In Thousands, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period (years)	1 year
Qualified Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding	292,350	330,730	377,480	360,130
Granted	49,000	61,000	35,000
Weighted average grant date fair value of options granted	$ 20.56	$ 14.76	$ 12.50
Total unrecognized compensation cost related to non-vested share-based compensation arrangements	$ 1,322
Period cost is expected to be recognized (years)	5 years
Exercise of stock options, shares	81,880	99,650	15,650
Non Qualified Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding	114,700	89,700	112,800	102,400
Granted	25,000	0	30,000
Award vesting period (years)	1 year
Weighted average grant date fair value of options granted	$ 20.56		$ 12.50
Total unrecognized compensation cost related to non-vested share-based compensation arrangements	213
Period cost is expected to be recognized (years)	5 years
Exercise of stock options, shares	0	23,100	14,600
Proceeds from stock options exercised	0	315	167
Tax deductions from the exercise of stock options	0	284	178
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual vesting percentage of award	25.00%
Total unrecognized compensation cost related to non-vested share-based compensation arrangements	$ 90
Period cost is expected to be recognized (years)	4 years
Weighted average remaining contractual life (years)	2 years 1 month 2 days	2 years 7 months 24 days	3 years 5 months 23 days
1994 Incentive Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual vesting percentage of award	20.00%
Options outstanding	3,000
2005 Incentive Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual vesting percentage of award	20.00%
Granted	49,000,000	61,000,000	35,000,000
2005 Incentive Stock Option Plan | Qualified Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock reserved for options to be issued	500,000
2009 Equity Incentive Plan | Non Qualified Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual vesting percentage of award	20.00%
Shares of common stock reserved for options to be issued	400,000