Consolidated Statements of Changes in Stockholders' Equity (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	$ 1,117	$ 482
Unrealized holding losses arising during period, net of $482 in taxes and $164 in realized net gains	148	164
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax, Total	189	63
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	127	350
Additional Paid In Capital
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	121	350
Accumulated Other Comprehensive Income (Loss)
Other Comprehensive Income (Loss), Unrealized Holding Gain (Loss) on Securities Arising During Period, Tax	1,117	482
Unrealized holding losses arising during period, net of $482 in taxes and $164 in realized net gains	148	164
Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Tax, Total	$ 189	$ 63
Class A common stock
Conversion of class B common stock to class A common stock, 14,500 shares	2,500	14,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period	6	350
Class A and Class B common stock	$ 0.12	$ 0.12
Class A common stock | Retained Earnings
Class A and Class B common stock		$ 0.12
Class B common stock
Conversion of class B common stock to class A common stock, 14,500 shares	2,500	14,500
Class A and Class B common stock	$ 0.06	$ 0.06
Class B common stock | Retained Earnings
Class A and Class B common stock	$ 0.06