Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Net earnings	$ 55,627	$ 72,897	$ 45,484
Unrealized gains (losses) on securities:
Net unrealized holding gains (losses) arising during period	10,955	33,417	82,686
Net unrealized liquidity gains (losses)	(215)	600	(3,312)
Reclassification adjustment for net amounts included in net earnings	(4,365)	(2,566)	2,756
Amortization of net unrealized (gains) losses related to transferred securities	27	9	(34)
Net unrealized gains (losses) on securities	6,402	31,460	82,096
Foreign currency translation adjustments	(217)	(308)	(73)
Benefit plans:
Amortization of net prior service cost and net gain	(3,417)	1,496	1,095
Other comprehensive income (loss)	2,768	32,648	83,118
Comprehensive income (loss)	$ 58,395	$ 105,545	$ 128,602