Regulatory Capital (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Tier One Leverage Capital [Abstract]
Tier One Leverage Capital	$ 1,138,988	$ 1,115,834
Tier One Leverage Capital to Average Assets	11.60%	12.10%
Tier One Leverage Capital Required for Capital Adequacy	393,693	367,909
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized	492,117	459,886
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	5.00%	5.00%
Tier One Risk Based Capital [Abstract]
Tier One Risk Based Capital	1,138,988	1,115,834
Tier One Risk Based Capital to Risk Weighted Assets	14.90%	17.50%
Tier One Risk Based Capital Required for Capital Adequacy	306,509	255,750
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	4.00%	4.00%
Tier One Risk Based Capital Required to be Well Capitalized	459,764	383,625
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	6.00%	6.00%
Capital [Abstract]
Capital	1,235,422	1,196,773
Capital to Risk Weighted Assets	16.10%	18.70%
Capital Required for Capital Adequacy	613,018	511,499
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Capital Required to be Well Capitalized	766,273	639,374
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%
Sterling Bank
Tier One Leverage Capital [Abstract]
Tier One Leverage Capital	1,112,281	1,100,443
Tier One Leverage Capital to Average Assets	11.30%	12.00%
Tier One Leverage Capital Required for Capital Adequacy	393,604	368,053
Tier One Leverage Capital Required for Capital Adequacy to Average Assets	4.00%	4.00%
Tier One Leverage Capital Required to be Well Capitalized	492,005	460,066
Tier One Leverage Capital Required to be Well Capitalized to Average Assets	5.00%	5.00%
Tier One Risk Based Capital [Abstract]
Tier One Risk Based Capital	1,112,281	1,100,443
Tier One Risk Based Capital to Risk Weighted Assets	14.50%	17.20%
Tier One Risk Based Capital Required for Capital Adequacy	306,681	255,875
Tier One Risk Based Capital Required for Capital Adequacy to Risk Weighted Assets	4.00%	4.00%
Tier One Risk Based Capital Required to be Well Capitalized	460,021	383,812
Tier One Risk Based Capital Required to be Well Capitalized to Risk Weighted Assets	6.00%	6.00%
Capital [Abstract]
Capital	1,208,768	1,181,421
Capital to Risk Weighted Assets	15.80%	18.50%
Capital Required for Capital Adequacy	613,361	511,749
Capital Required for Capital Adequacy to Risk Weighted Assets	8.00%	8.00%
Capital Required to be Well Capitalized	$ 766,701	$ 639,687
Capital Required to be Well Capitalized to Risk Weighted Assets	10.00%	10.00%