Parent Company Financial Statements (Statements of Cash Flows) (Details) - USD ($)	3 Months Ended										12 Months Ended
	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016		Dec. 31, 2015		Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Operating Activities
Net income	$ 10,902,000	$ 10,903,000	$ 9,616,000	$ 8,646,000	[1]	$ 1,692,000	[2]	$ 6,456,000	$ 7,193,000	$ 5,611,000	$ 40,067,000	$ 20,952,000	$ 24,570,000
Depreciation and amortization expense											4,426,000	3,614,000	3,051,000
Stock-based compensation expense											1,997,000	836,000	599,000
(Increase) decrease in other assets											11,329,000	(7,062,000)	(3,349,000)
Net cash provided by operating activities											57,418,000	15,918,000	29,886,000
Investing Activities
Proceeds from sale of assets											90,000	0	0
Purchase of premises and equipment											(1,671,000)	(3,189,000)	(1,316,000)
Net cash used in investing activities											(167,953,000)	(54,744,000)	(170,512,000)
Financing Activities
Issuance of subordinated debt, net of issuance costs											0	14,464,000	0
Exercise of stock options and issuance of restricted stock, net of repurchase for tax withholdings and tax benefit											(894,000)	(753,000)	(328,000)
Equity issuance costs											0	(612,000)	0
Common stock repurchases											0	0	(7,475,000)
Cash dividends paid on common stock and cash in lieu for fractional shares paid due to stock split											(12,394,000)	(9,785,000)	(8,085,000)
Net cash provided by financing activities											118,754,000	57,501,000	150,084,000
Net increase in cash and cash equivalents											8,219,000	18,675,000	9,458,000
Cash and cash equivalents at beginning of year				79,488,000						60,813,000	79,488,000	60,813,000	51,355,000
Cash and cash equivalents at end of year	87,707,000					79,488,000					87,707,000	79,488,000	60,813,000
Parent Company [Member]
Operating Activities
Net income											40,067,000	20,952,000	24,570,000
Equity in undistributed (income) losses of subsidiaries											(26,651,000)	4,573,000	(13,799,000)
Depreciation and amortization expense											(4,000)	0	0
(Increase) decrease in receivable from subsidiaries											1,819,000	(1,901,000)	2,037,000
(Increase) decrease in other assets											1,213,000	(2,175,000)	165,000
Increase (decrease) in due to subsidiaries											(1,179,000)	1,216,000	0
Increase (decrease) in other liabilities											(2,519,000)	320,000	(2,106,000)
Net cash provided by operating activities											12,746,000	22,985,000	10,867,000
Investing Activities
Acquisition of SBM, net of cash acquired											0	(25,319,000)	0
Proceeds from Sale of Available-for-sale Securities, Equity											80,000	0	0
Proceeds from sale of assets											0	0	5,237,000
Net cash used in investing activities											80,000	(25,319,000)	5,237,000
Financing Activities
Issuance of subordinated debt, net of issuance costs											0	14,464,000	0
Exercise of stock options and issuance of restricted stock, net of repurchase for tax withholdings and tax benefit											(894,000)	(753,000)	(328,000)
Capital contribution from subsidiaries											1,997,000	836,000	599,000
Equity issuance costs											0	(612,000)	0
Common stock repurchases											0	0	(7,475,000)
Cash dividends paid on common stock and cash in lieu for fractional shares paid due to stock split											(12,393,000)	(9,785,000)	(8,085,000)
Net cash provided by financing activities											(9,502,000)	5,656,000	(14,633,000)
Net increase in cash and cash equivalents											3,324,000	3,322,000	1,471,000
Cash and cash equivalents at beginning of year				$ 26,581,000						$ 23,259,000	26,581,000	23,259,000	21,788,000
Cash and cash equivalents at end of year	$ 29,905,000					$ 26,581,000					$ 29,905,000	$ 26,581,000	$ 23,259,000

[1] (1)In the second quarter of 2016, the Company adopted ASU 2016-09 effective as of January 1, 2016. As such, first quarter 2016 financial results have been restated from previously reported within Form 10-Q.

[2] On October 16, 2015, the Company completed its acquisition of SBM. Fourth quarter 2015 results of operations include revenues and expenses incurred as a combined organization from the acquisition date through December 31, 2015. The decrease in basic and diluted EPS in the fourth quarter of 2015 was due to acquisition costs and the issuance of 4.1 million shares of Company common stock (as adjusted for the three-for-two common stock split effective September 30, 2016) in connection with the acquisition. Refer to Note 2 for additional details of the acquisition