Consolidated Balance Sheets Parenthetical - shares	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015
Statement of Financial Position [Abstract]
Common stock, shares authorized	300,000,000	300,000,000	300,000,000
Common stock, shares issued	170,183,515	170,183,515	170,183,515
Non-cumulative Perpetual Preferred Stock, Series A, Shares Authorized	115,000	115,000	115,000
Non-Cumulative Perpetual Preferred stock, Series A, Shares Outstanding	100,000	100,000	100,000
Treasury stock, at cost	4,463,581	4,425,927	4,730,374