Consolidated Statements of Changes in Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Employee Stock Ownership Plan	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Common Stock Acquired by Deferred Compensation Plan	Deferred Compensation Plan Liability	Sun Bancorp, Inc.	Sun Bancorp, Inc. Common Stock	Sun Bancorp, Inc. Additional Paid-In Capital	Sun Bancorp, Inc. Treasury Stock	Capital Bank of New Jersey	Capital Bank of New Jersey Common Stock	Capital Bank of New Jersey Additional Paid-In Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Effect of adopting Accounting Standards Update (ASU) | Accounting Standards Update 2016-01	$ 0					$ (147)	$ 147
Beginning Balance at Dec. 31, 2017	601,941	$ (2,479)	$ 0	$ 336	$ 354,377	271,023	(5,349)	$ (15,967)	$ (84)	$ 84
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	15,702					15,702
Other comprehensive income, net of tax	1,652						1,652
Stock awards	979			0	979
Acquisition of common stock by ESOP	(8,400)	(8,400)			0
Allocation of ESOP stock	483	357			126
Cash dividend per share	(7,169)					(7,169)
Exercise of stock options	1,861			1	5,638	(3,778)		0
Ending Balance at Mar. 31, 2018	1,007,460	(2,189)	0	481	745,480	268,994	(5,306)	0	(84)	84
Beginning Balance at Dec. 31, 2017	601,941	(2,479)	0	336	354,377	271,023	(5,349)	(15,967)	(84)	84
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	21,129					21,129
Other comprehensive income, net of tax	1,548						1,548
Stock awards	1,787			2	1,785
Acquisition of common stock by ESOP	(8,400)	(8,400)
Allocation of ESOP stock	966	647			319
Cash dividend per share	(14,274)					(14,274)
Exercise of stock options	5,317			3	9,094	(3,982)		202
Acquisition, value											$ 402,554	$ 141	$ 386,648	$ 15,765
Ending Balance at Jun. 30, 2018	1,012,568	(10,232)	0	482	752,223	273,749	(3,654)	0	(84)	84
Beginning Balance at Mar. 31, 2018	1,007,460	(2,189)	0	481	745,480	268,994	(5,306)	0	(84)	84
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	15,702
Other comprehensive income, net of tax	1,652
Ending Balance at Jun. 30, 2018	1,012,568	(10,232)	0	482	752,223	273,749	(3,654)	0	(84)	84
Beginning Balance at Dec. 31, 2018	1,039,358	(9,857)	0	483	757,963	305,056	(3,450)	(10,837)	(87)	87
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	40,153					40,153
Other comprehensive income, net of tax	1,807						1,807
Stock awards	2,602			2	2,600
Allocation of ESOP stock	801	605			196
Cash dividend per share	(17,304)					(17,304)
Exercise of stock options	795			1	1,402	(608)		0
Purchase of shares of common stock	(7,398)							(7,398)
Sale (purchase) of stock for the deferred compensation plan	0								(3)	3
Acquisition, value															$ 76,481	$ 32	$ 76,449
Ending Balance at Jun. 30, 2019	1,137,295	(9,252)	0	518	838,610	327,297	(1,643)	(18,235)	(90)	90
Beginning Balance at Mar. 31, 2019	1,127,163	(9,554)		518	836,546	316,976	(2,681)	(14,642)	(89)	89
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	18,980					18,980
Other comprehensive income, net of tax	1,038						1,038
Stock awards	1,690			0	1,690
Allocation of ESOP stock	401	302			99
Cash dividend per share	(8,660)					(8,660)
Exercise of stock options	276			0	275	1		0
Purchase of shares of common stock	(3,593)							(3,593)
Sale (purchase) of stock for the deferred compensation plan	0								(1)	1
Ending Balance at Jun. 30, 2019	$ 1,137,295	$ (9,252)	$ 0	$ 518	$ 838,610	$ 327,297	$ (1,643)	$ (18,235)	$ (90)	$ 90