Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net earnings	$ 92,558	$ 55,627	$ 72,897
Unrealized gains (losses) on securities:
Net unrealized holding gains (losses) arising during period	27,211	10,955	33,417
Net unrealized liquidity gains (losses)	1,307	(215)	600
Reclassification adjustment for net amounts included in net earnings	(4,504)	(4,365)	(2,566)
Amortization of net unrealized (gains) losses related to transferred securities	148	27	9
Net unrealized gains (losses) on securities	24,162	6,402	31,460
Foreign currency translation adjustments	221	(217)	(308)
Benefit plans:
Amortization of net prior service cost and net gain	(773)	(3,417)	1,496
Other comprehensive income (loss)	23,610	2,768	32,648
Comprehensive income (loss)	$ 116,168	$ 58,395	$ 105,545