Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015
Investment securities available for sale [Abstract]
Alternative investments		$ 8,300	$ 7,600
Assets and liabilities measured at fair value on a nonrecurring basis [Abstract]
Valuation allowance of impaired loans		1,100	3,700
Other Liabilities [Member]
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, beginning of period		0	0
Total realized gains included in income		0	0
Change in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at period end		0	0
Purchases		0	0
Issuances		0	0
Settlements		0	0
Transfers out of Level 3		0	0
Fair value, September 30		0	0
Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at period end		0	0
Recurring [Member]
Investment securities available for sale [Abstract]
U.S. treasury securities		250
U.S. government agency securities		21,769	128,193
Mortgage-backed securities		976,626	582,916
State and municipal securities		212,720	165,042
Agency- backed securities		78,580	48,801
Corporate notes and other		8,601	10,113
Total investment securities available-for-sale		1,298,546	935,065
Alternative investments		10,478	9,764
Other assets		13,340	15,147
Total assets at fair value		1,322,364	959,976
Liabilities at fair value [Abstract]
Other liabilities		15,758	16,568
Total liabilities at fair value		15,758	16,568
Recurring [Member] | Quoted Market Prices in an Active Market (Level 1) [Member]
Investment securities available for sale [Abstract]
U.S. treasury securities		0
U.S. government agency securities		0	0
Mortgage-backed securities		0	0
State and municipal securities		0	0
Agency- backed securities		0	0
Corporate notes and other		0	0
Total investment securities available-for-sale		0	0
Alternative investments		0	0
Other assets		0	0
Total assets at fair value		0	0
Liabilities at fair value [Abstract]
Other liabilities		0	0
Total liabilities at fair value		0	0
Recurring [Member] | Models with Significant Observable Market Parameters (Level 2) [Member]
Investment securities available for sale [Abstract]
U.S. treasury securities		250
U.S. government agency securities		21,769	128,193
Mortgage-backed securities		976,626	582,916
State and municipal securities		212,720	165,042
Agency- backed securities		78,580	48,801
Corporate notes and other		8,601	10,113
Total investment securities available-for-sale		1,298,546	935,065
Alternative investments		0	0
Other assets		13,340	15,147
Total assets at fair value		1,311,886	950,212
Liabilities at fair value [Abstract]
Other liabilities		15,758	16,568
Total liabilities at fair value		15,758	16,568
Recurring [Member] | Models with Significant Unobservable Market Parameters (Level 3) [Member]
Investment securities available for sale [Abstract]
U.S. treasury securities		0
U.S. government agency securities		0	0
Mortgage-backed securities		0	0
State and municipal securities		0	0
Agency- backed securities		0	0
Corporate notes and other		0	0
Total investment securities available-for-sale		0	0
Alternative investments		10,478	9,764
Other assets		0	0
Total assets at fair value		10,478	9,764
Liabilities at fair value [Abstract]
Other liabilities		0	0
Total liabilities at fair value		0	0
Nonrecurring [Member]
Assets and liabilities measured at fair value on a nonrecurring basis [Abstract]
Other real estate owned		6,090	5,083
Collateral dependent nonaccrual loans, net	[1]	26,506	25,690
Total		32,596	30,773
Total losses on other real estate owned		(135)	(41)
Total losses on collateral dependent nonaccrual loans, net	[1]	(7,173)	(2,637)
Total losses		(7,308)	(2,678)
Nonrecurring [Member] | Quoted Market Prices in an Active Market (Level 1) [Member]
Assets and liabilities measured at fair value on a nonrecurring basis [Abstract]
Other real estate owned		0	0
Collateral dependent nonaccrual loans, net	[1]	0	0
Total		0	0
Nonrecurring [Member] | Models with Significant Observable Market Parameters (Level 2) [Member]
Assets and liabilities measured at fair value on a nonrecurring basis [Abstract]
Other real estate owned		0	0
Collateral dependent nonaccrual loans, net	[1]	0	0
Total		0	0
Nonrecurring [Member] | Models with Significant Unobservable Market Parameters (Level 3) [Member]
Assets and liabilities measured at fair value on a nonrecurring basis [Abstract]
Other real estate owned		6,090	5,083
Collateral dependent nonaccrual loans, net	[1]	26,506	25,690
Total		32,596	30,773
Other Assets [Member]
Assets measured on recurring basis, unobservable input reconciliation, calculation [Roll Forward]
Fair value, beginning of period		9,764	8,004
Total realized gains included in income		131	149
Change in unrealized gains/losses included in other comprehensive income for assets and liabilities still held at period end		0	0
Purchases		1,639	2,254
Issuances		0	0
Settlements		(1,057)	(643)
Transfers out of Level 3		0	0
Fair value, September 30		10,477	9,764
Total realized gains included in income related to financial assets and liabilities still on the consolidated balance sheet at period end		$ 131	$ 149

[1] Amount is net of a valuation allowance of $1.1 million and $3.7 million at December 31, 2016 and 2015, respectively, as required by ASC 310-10, "Receivables."