Accumulated Other Comprehensive Income (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended		3 Months Ended		9 Months Ended		3 Months Ended	9 Months Ended							3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013 Unrealized Gains (Losses) Investment Securities	Sep. 30, 2012 Unrealized Gains (Losses) Investment Securities	Sep. 30, 2013 Unrealized Gains (Losses) Investment Securities	Sep. 30, 2012 Unrealized Gains (Losses) Investment Securities	Sep. 30, 2012 Unrealized Gains (Losses) Cash Flow Hedges	Sep. 30, 2013 Unrealized Gains (Losses) Cash Flow Hedges	Sep. 30, 2012 Unrealized Gains (Losses) Cash Flow Hedges	Sep. 30, 2012 Retirement Plan Liabilities Adjustments	Sep. 30, 2013 Retirement Plan Liabilities Adjustments	Jun. 30, 2013 Retirement Plan Liabilities Adjustments	Dec. 31, 2012 Retirement Plan Liabilities Adjustments	Jun. 30, 2012 Retirement Plan Liabilities Adjustments	Sep. 30, 2013 Foreign Currency Translation Adjustments	Sep. 30, 2012 Foreign Currency Translation Adjustments	Sep. 30, 2013 Foreign Currency Translation Adjustments	Sep. 30, 2012 Foreign Currency Translation Adjustments
Changes in accumulated other comprehensive income (loss)
Balance at beginning of period	$ 23,420	$ (6,098)	$ 29,606	$ (25,538)	$ 9,079	$ 12,854	$ 17,255	$ 5,213	$ 1,511	$ 104	$ 4,318	$ (35,221)	$ 8,120	$ 8,120	$ 8,120	$ (21,828)	$ 6,221	$ 1,365	$ 4,127	$ 152
Other comprehensive income before reclassifications	(2,271)	5,577	(7,036)	16,549	(215)	2,510	(7,074)	9,918			(11,042)	13,393					(2,056)	3,067	38	4,280
Reclassification adjustments from accumulated other comprehensive income	(6)	(384)	(1,427)	8,084	(6)	390	(1,323)	623	(774)	(104)	7,461
Balance at end of period	$ 21,143	$ (905)	$ 21,143	$ (905)	$ 8,858	$ 15,754	$ 8,858	$ 15,754	$ 737		$ 737	$ (21,828)	$ 8,120	$ 8,120	$ 8,120	$ (21,828)	$ 4,165	$ 4,432	$ 4,165	$ 4,432