Fair Value (Details) - Fair Value Measurements - USD ($) $ in Thousands		Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013
Trading securities:
Total trading securities		$ 18,172		$ 17,460
Securities available-for-sale:
CDOs		32,004	$ 33,928	33,774	$ 18,436	$ 21,666	$ 18,309
Total available-for-sale securities		1,142,407		1,187,009
Level 1
Trading securities:
Money market funds		1,595		1,725
Mutual funds		16,577		15,735
Total trading securities		18,172		17,460
Securities available-for-sale:
U.S. agency securities		0		0
CMOs		0		0
MBSs		0		0
Municipal securities		0		0
CDOs		0		0
Corporate debt securities		0		0
Equity securities		0		0
Total available-for-sale securities		0		0
Mortgage servicing rights	[1]	0		0
Derivative assets	[1]	0		0
Liabilities:
Derivative liabilities	[2]	0		0
Level 2
Trading securities:
Money market funds		0		0
Mutual funds		0		0
Total trading securities		0		0
Securities available-for-sale:
U.S. agency securities		20,484		30,431
CMOs		521,575		534,156
MBSs		181,843		159,765
Municipal securities		382,988		423,820
CDOs		0		0
Corporate debt securities		80		1,802
Equity securities		3,433		3,261
Total available-for-sale securities		1,110,403		1,153,235
Mortgage servicing rights	[1]	0		0
Derivative assets	[1]	11,341		9,018
Liabilities:
Derivative liabilities	[2]	16,691		11,980
Level 3
Trading securities:
Money market funds		0		0
Mutual funds		0		0
Total trading securities		0		0
Securities available-for-sale:
U.S. agency securities		0		0
CMOs		0		0
MBSs		0		0
Municipal securities		0		0
CDOs		32,004		33,774
Corporate debt securities		0		0
Equity securities		0		0
Total available-for-sale securities		32,004		33,774
Mortgage servicing rights	[1]	1,820		1,728
Derivative assets	[1]	0		0
Liabilities:
Derivative liabilities	[2]	$ 0		$ 0

[1] Included in other assets in the Consolidated Statements of Financial Condition.

[2] Included in other liabilities in the Consolidated Statements of Financial Condition.