Regulatory Matters (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Compliance with Regulatory Capital Requirements under Banking Regulations [Line Items]
Amount Available for Dividend Distribution without Affecting Capital Adequacy Requirements	$ 220,000
Maximum Allowed Percentage Of Loans Issued To A Single Affiliate	10.00%
Maximum Allowed Percentage Of Aggregate Loans Issued To All Affiliate	20.00%
Total Capital [Abstract]
Capital	$ 2,837,801	$ 2,179,197
Capital to risk weighted assets	0.144	0.118
Capital required for capital adequacy	$ 1,571,876	$ 1,481,425
Capital required for capital adequacy to risk weighted assets	0.080	0.080
Tier One Risk Based Capital [Abstract]
Tier one risk based capital	$ 2,067,640	$ 1,796,987
Tier one risk based capital to risk weighted assets	0.105	0.097
Tier one risk based capital required for capital adequacy	$ 1,178,907	$ 1,111,068
Tier one risk based capital required for capital adequacy to risk weighted assets	0.060	0.060
CommonEquityTierOneCapitalAbstract [Abstract]
Common equity tier 1 capital	$ 1,874,762	$ 1,796,987
Common equity tier one capital ratio	0.095	0.097
Common equity tier one capital required for capital adequacy	$ 884,181	$ 833,301
Common equity tier one capital required for capital adequacy to risk weighted assets	4.50%	4.50%
Tier One Leverage Capital [Abstract]
Tier one leverage capital	$ 2,067,640	$ 1,796,987
Tier one leverage capital to average assets	0.082	0.084
Tier one leverage capital required for capital adequacy	$ 1,009,469	$ 850,727
Tier one leverage capital required for capital adequacy to average assets	0.040	0.040
Fulton Bank, N.A.
Total Capital [Abstract]
Capital	$ 2,758,963	$ 2,224,505
Capital to risk weighted assets	0.141	0.121
Capital required for capital adequacy	$ 1,562,322	$ 1,473,880
Capital required for capital adequacy to risk weighted assets	0.080	0.080
Capital required to be well capitalized	$ 1,952,903	$ 1,842,350
Capital required to be well capitalized to risk weighted assets	0.100	0.100
Tier One Risk Based Capital [Abstract]
Tier one risk based capital	$ 2,529,802	$ 2,058,295
Tier one risk based capital to risk weighted assets	0.130	0.112
Tier one risk based capital required for capital adequacy	$ 1,171,742	$ 1,105,410
Tier one risk based capital required for capital adequacy to risk weighted assets	0.060	0.060
Tier one risk based capital required to be well capitalized	$ 1,562,322	$ 1,473,880
Tier one risk based capital required to be well capitalized to risk weighted assets	0.080	0.080
CommonEquityTierOneCapitalAbstract [Abstract]
Common equity tier 1 capital	$ 2,485,802	$ 2,014,295
Common equity tier one capital ratio	0.127	0.109
Common equity tier one capital required for capital adequacy	$ 878,806	$ 829,057
Common equity tier one capital required for capital adequacy to risk weighted assets	4.50%	4.50%
Common equity tier one capital required to be well-capitalized	$ 1,269,387	$ 1,197,527
Common equity tier one capital required to be well capitalized to risk weighted assets	6.50%	6.50%
Tier One Leverage Capital [Abstract]
Tier one leverage capital	$ 2,529,802	$ 2,058,295
Tier one leverage capital to average assets	0.101	0.098
Tier one leverage capital required for capital adequacy	$ 1,001,313	$ 844,341
Tier one leverage capital required for capital adequacy to average assets	0.040	0.040
Tier one leverage capital required to be well capitalized	$ 1,251,641	$ 1,055,426
Tier one leverage capital required to be well capitalized to average assets	0.050	0.050