Other Comprehensive Income/Loss (Details 3) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Amounts reclassified from accumulated other comprehensive income to the consolidated statements of income
Compensation and benefits	$ 31,998	$ 42,160
Income tax benefit	7,781	5,566
Net of tax	(13,852)	(9,996)
Net actuarial loss and prior service cost adjustments on pension plans and other postretirement benefits | Amount Reclassified from Accumulated Other Comprehensive Income
Amounts reclassified from accumulated other comprehensive income to the consolidated statements of income
Net actuarial loss	967
Prior service cost	53
Compensation and benefits	1,020
Income tax benefit	(359)
Net of tax	$ 661