Consolidated Statements of Condition (Unaudited) (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Statement of Financial Position [Abstract]
Held-to-Maturity Securities, Fair Value	$ 4,378,007	$ 4,504,495
Common Stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common Stock, authorized shares	500,000,000us-gaap_CommonStockSharesAuthorized	500,000,000us-gaap_CommonStockSharesAuthorized
Common Stock, issued shares	57,733,267us-gaap_CommonStockSharesIssued	57,634,755us-gaap_CommonStockSharesIssued
Common Stock, outstanding shares	43,652,628us-gaap_CommonStockSharesOutstanding	43,724,208us-gaap_CommonStockSharesOutstanding
Treasury Stock, Shares	14,080,639us-gaap_TreasuryStockShares	13,910,547us-gaap_TreasuryStockShares

Face amount or stated value per share of common stock.

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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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