Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands		Sep. 30, 2017		Jun. 30, 2017	Dec. 31, 2016		Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		$ 714,355			$ 739,912
Mortgage loans held for sale, measured at fair value		28,500			29,400
Derivative assets		5,292			3,582
Derivative liabilities		6,321			4,043
Contingent consideration liability		1,737	[1]	$ 1,737	2,047	[1]	$ 2,047	$ 2,986	$ 2,945
Obligations of U.S. government agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		119,125			108,440
Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		561,670			588,085
Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		3,163			14,485
Individual name issuer trust preferred debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		26,388			26,736
Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		4,009			2,166
Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0			0
Derivative liabilities		0			0
Contingent consideration liability	[1]	0			0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		5,292			3,582
Derivative liabilities		6,321			4,043
Contingent consideration liability	[1]	0			0
Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets		0			0
Derivative liabilities		0			0
Contingent consideration liability	[1]	1,737			2,047
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale, measured at fair value		28,484			29,434
Total assets at fair value on a recurring basis		748,131			772,928
Total liabilities at fair value on a recurring basis		8,058			6,090
Recurring [Member] | Obligations of U.S. government agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		119,125			108,440
Recurring [Member] | Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		561,670			588,085
Recurring [Member] | Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		3,163			14,485
Recurring [Member] | Individual name issuer trust preferred debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		26,388			26,736
Recurring [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		4,009			2,166
Recurring [Member] | Level 1 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale, measured at fair value		0			0
Total assets at fair value on a recurring basis		0			0
Total liabilities at fair value on a recurring basis		0			0
Recurring [Member] | Level 1 [Member] | Obligations of U.S. government agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0			0
Recurring [Member] | Level 1 [Member] | Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0			0
Recurring [Member] | Level 1 [Member] | Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0			0
Recurring [Member] | Level 1 [Member] | Individual name issuer trust preferred debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0			0
Recurring [Member] | Level 1 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0			0
Recurring [Member] | Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale, measured at fair value		28,484			29,434
Total assets at fair value on a recurring basis		748,131			772,928
Total liabilities at fair value on a recurring basis		6,321			4,043
Recurring [Member] | Level 2 [Member] | Obligations of U.S. government agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		119,125			108,440
Recurring [Member] | Level 2 [Member] | Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		561,670			588,085
Recurring [Member] | Level 2 [Member] | Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		3,163			14,485
Recurring [Member] | Level 2 [Member] | Individual name issuer trust preferred debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		26,388			26,736
Recurring [Member] | Level 2 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		4,009			2,166
Recurring [Member] | Level 3 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale, measured at fair value		0			0
Total assets at fair value on a recurring basis		0			0
Total liabilities at fair value on a recurring basis		1,737			2,047
Recurring [Member] | Level 3 [Member] | Obligations of U.S. government agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0			0
Recurring [Member] | Level 3 [Member] | Mortgage-backed securities issued by U.S. government-sponsored agencies and U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0			0
Recurring [Member] | Level 3 [Member] | Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0			0
Recurring [Member] | Level 3 [Member] | Individual name issuer trust preferred debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		0			0
Recurring [Member] | Level 3 [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities		$ 0			$ 0

[1] The contingent consideration liability is included in other liabilities in the Unaudited Consolidated Balance Sheets.