Equity (Schedule Of Components Of Accumulated Other Comprehensive Income) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Schedule of Trading Securities and Other Trading Assets [Line Items]
Balance at beginning of year			$ 46,697
Increase in unrealized gains on securities	1,989	22,837	2,264	21,652
Increase in unrealized gains on cash flow hedges	5,233		6,379
Deferred tax liability on increase in unrealized gains and other accumulated other comprehensive income tax adjustments			(3,517)
Reclassification adjustment of net gains included in net income			(1,383)
Reclassification adjustment of net gains included in net income	(4)	(560)	(66)	(953)
Reclassification adjustment for tax expense on realized net gains			547
Balance at end of period	50,987		50,987
Accumulated Net Gain (Loss) from Designated or Qualifying Cash Flow Hedges [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Balance at beginning of year			1,557
Increase in unrealized gains on cash flow hedges			6,379
Deferred tax liability on increase in unrealized gains and other accumulated other comprehensive income tax adjustments			(2,522)
Reclassification adjustment of net gains included in net income			(1,317)
Reclassification adjustment for tax expense on realized net gains			521
Balance at end of period	4,618		4,618
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Schedule of Trading Securities and Other Trading Assets [Line Items]
Balance at beginning of year			45,140	20,078
Increase in unrealized gains on securities			2,264	21,652
Deferred tax liability on increase in unrealized gains and other accumulated other comprehensive income tax adjustments			(995)	(8,619)
Reclassification adjustment of net gains included in net income			(66)	(953)
Reclassification adjustment for tax expense on realized net gains			26	377
Balance at end of period	$ 46,369	$ 32,535	$ 46,369	$ 32,535