Regulatory Matters (Tables)

12 Months Ended

Dec. 31, 2013

REGULATORY MATTERS [Abstract]

Schedule of Compliance with Regulatory Capital Requirements under Banking Regulations [Table Text Block]

	Actual				For capital adequacy purposes (at least)				To be well capitalized under prompt corrective action provisions (at least)
	Amount		Ratio		Amount		Ratio		Amount		Ratio
	(In thousands)
As of December 31, 2013
Total risk-based capital
Company	$	689,767	14.77	%	$	373,483	8.0	%	$	466,854	10.0	%
Boston Private Bank	631,510		13.63		354,285		8.0		442,856		10.0
Tier I risk-based capital
Company	631,041		13.52		186,741		4.0		280,112		6.0
Boston Private Bank	573,340		12.37		177,112		4.0		265,714		6.0
Tier I leverage capital
Company	631,041		10.09		250,085		4.0		312,606		5.0
Boston Private Bank	573,340		9.27		239,663		4.0		299,579		5.0
As of December 31, 2012
Total risk-based capital
Company	$	676,206	14.61	%	$	370,223	8.0	%	$	462,779	10.0	%
Boston Private Bank	594,422		12.94		367,522		8.0		459,402		10.0
Tier I risk-based capital
Company	617,965		13.35		185,112		4.0		277,667		6.0
Boston Private Bank	536,649		11.68		183,761		4.0		275,641		6.0
Tier I leverage capital
Company	617,965		9.94		248,692		4.0		310,865		5.0
Boston Private Bank	536,649		8.73		245,755		4.0		307,194		5.0