Fair Value Measurements (Assets and Liabilities Measured at Fair Value on a Recurring Basis) (Details) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	$ 787,842	$ 780,954
Mortgage loans held for sale, measured at fair value	17,494	26,943
Derivative assets	13,489	2,759
Derivative liabilities	11,568	3,047
Contingent consideration liability	187	1,404	$ 1,737	$ 2,047
Obligations of U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	165,614	157,604
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	589,747	590,882
Obligations of states and political subdivisions [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	2,359	2,359
Individual name issuer trust preferred debt securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	17,096	16,984
Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	13,026	13,125
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	0	0
Level 2 [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivative assets	13,489	2,759
Derivative liabilities	11,568	3,047
Contingent consideration liability	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	187	1,404
Recurring [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Mortgage loans held for sale, measured at fair value	17,494	26,943
Total assets at fair value on a recurring basis	818,825	810,656
Total liabilities at fair value on a recurring basis	11,755	4,451
Recurring [Member] | Obligations of U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	165,614	157,604
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	589,747	590,882
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	2,359	2,359
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	17,096	16,984
Recurring [Member] | Corporate bonds [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	13,026	13,125
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-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	17,494	26,943
Total assets at fair value on a recurring basis	818,825	810,656
Total liabilities at fair value on a recurring basis	11,568	3,047
Recurring [Member] | Level 2 [Member] | Obligations of U.S. government-sponsored enterprises [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Available for sale securities	165,614	157,604
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	589,747	590,882
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	2,359	2,359
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	17,096	16,984
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	13,026	13,125
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	187	1,404
Recurring [Member] | Level 3 [Member] | Obligations of 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