Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2014

Fair Value Disclosures [Abstract]

Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Recurring Basis

Financial assets and financial liabilities measured at fair value on a recurring basis are as follows:

			Fair Value Measurements at Reporting Date Using
As of December 31, 2014	Balance		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Investment securities available-for-sale:
Obligations of U.S. government agencies	$	720,933	$	—	$	720,933	$	—
U.S. agency mortgage-backed securities & collateralized mortgage obligations	990,666		—		990,666		—
Private mortgage-backed securities	325		—		325		—

			Fair Value Measurements at Reporting Date Using
As of December 31, 2013	Balance		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Investment securities available-for-sale:
Obligations of U.S. government agencies	$	763,238	$	—	$	763,238	$	—
U.S. agency mortgage-backed securities & collateralized mortgage obligations	1,184,053		—		1,184,053		—
Private mortgage-backed securities	415		—		415		—

Schedule of Financial Assets and Financial Liabilities Measured at Fair Value on a Non-Recurring Basis

The following table presents information about the Company’s assets and liabilities measured at fair value on a non-recurring basis.

			Fair Value Measurements at Reporting Date Using
As of December 31, 2014	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs  (Level 2)		Significant Unobservable Inputs (Level 3)		Total Gains (Losses)
Impaired loans	$	30,494	$	—	$	—	$	30,494	$	(14,552	)
Other real estate owned	4,554		—		—		4,554		(12,665		)
Long-lived assets to be disposed of by sale	1,083		—		—		1,083		(702		)

			Fair Value Measurements at Reporting Date Using
As of December 31, 2013	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total Gains (Losses)
Impaired loans	$	57,302	$	—	$	—	$	57,302	$	(23,224	)
Other real estate owned	8,502		—		—		8,502		(14,441		)
Long-lived assets to be disposed of by sale	1,186		—		—		1,186		(599		)

Fair Value Inputs, Assets, Quantitative Information

As of December 31, 2014	Fair Value		Valuation Technique	Unobservable Inputs	Range (Weighted Average)
Impaired loans	$	30,494	Appraisal	Appraisal adjustment	0%	-	51%	(19%)
Other real estate owned	4,554		Appraisal	Appraisal adjustment	0%	-	50%	(15%)
Long-lived assets to be disposed of by sale	1,083		Appraisal	Appraisal adjustment	0%	-	9%	(5%)
As of December 31, 2013	Fair Value		Valuation Technique	Unobservable Inputs	Range (Weighted Average)
Impaired loans	$	57,302	Appraisal	Appraisal adjustment	6%	-	66%	(31%)
Other real estate owned	8,502		Appraisal	Appraisal adjustment	6%	-	55%	(15%)
Long-lived assets to be disposed of by sale	1,186		Appraisal	Appraisal adjustment	0%	-	9%	(6%)

Fair Value, by Balance Sheet Grouping

A summary of the estimated fair values of financial instruments follows:

	`				Fair Value Measurements at Reporting Date Using
As of December 31, 2014	Carrying Amount		Estimated Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Financial assets:
Cash and cash equivalents	$	798,670	$	798,670	$	798,670	$	—	$	—
Investment securities available-for-sale	1,711,924		1,711,924		—		1,711,924		—
Investment securities held-to-maturity	575,186		584,533		—		584,533		—
Accrued interest receivable	27,063		27,063		—		27,063		—
Mortgage servicing rights, net	14,038		21,434		—		21,434		—
Net loans	4,823,243		4,800,725		—		4,770,231		30,494
Total financial assets	$	7,950,124	$	7,944,349	$	798,670	$	7,115,185	$	30,494
Financial liabilities:
Total deposits, excluding time deposits	$	5,767,992	$	5,767,992	$	5,767,992	$	—	$	—
Time deposits	1,238,220		1,244,324		—		1,244,324		—
Securities sold under repurchase agreements	502,250		502,250		—		502,250		—
Other borrowed funds	9		9		—		9		—
Accrued interest payable	5,833		5,833		—		5,833		—
Long-term debt	38,067		37,781		—		37,781		—
Subordinated debentures held by subsidiary trusts	82,477		75,734		—		75,734		—
Total financial liabilities	$	7,634,848	$	7,633,923	$	5,767,992	$	1,865,931	$	—

					Fair Value Measurements at Reporting Date Using
As of December 31, 2013	Carrying Amount		Estimated Fair Value		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
Financial assets:
Cash and cash equivalents	$	534,827	$	534,827	$	534,827	$	—	$	—
Investment securities available-for-sale	1,947,706		1,947,706		—		1,947,706		—
Investment securities held-to-maturity	203,837		205,926		—		205,926		—
Accrued interest receivable	26,450		26,450		—		26,450		—
Mortgage servicing rights, net	13,546		25,698		—		25,698		—
Net loans	4,259,514		4,246,539		—		4,189,237		57,302
Total financial assets	$	6,985,880	$	6,987,146	$	534,827	$	6,395,017	$	57,302
Financial liabilities:
Total deposits, excluding time deposits	$	4,943,033	$	4,943,033	$	4,943,033	$	—	$	—
Time deposits	1,190,717		1,196,250		—		1,196,250		—
Securities sold under repurchase agreements	457,437		457,437		—		457,437		—
Other borrowed funds	3		3		—		3		—
Accrued interest payable	4,963		4,963		—		4,963		—
Long-term debt	36,917		34,508		—		34,508		—
Subordinated debentures held by subsidiary trusts	82,477		72,045		—		72,045		—
Total financial liabilities	$	6,715,547	$	6,708,239	$	4,943,033	$	1,765,206	$	—