Goodwill and Other Intangible Assets Summary of Core Deposit and Other Intangibles (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Summary of core deposit intangibles and other intangibles
Amortization of other intangible assets	$ 885	$ 990	$ 2,574	$ 2,972
Core Deposit Intangibles [Member]
Summary of core deposit intangibles and other intangibles
Gross carrying amount	36,230		36,230		$ 36,230
Accumulated amortization	(35,759)		(35,759)		(34,433)
Amortization Expense	471		471		1,797
Amortization of other intangible assets			1,326		2,868
Other Intangibles [Member]
Summary of core deposit intangibles and other intangibles
Gross carrying amount	31,398		31,398		19,283
Accumulated amortization	(14,891)		(14,891)		(13,643)
Amortization Expense	$ 16,507		16,507		5,640
Additions during the period			12,115		0
Amortization of other intangible assets			$ 1,248		$ 879