ACCOUNTING POLICIES (Details) (USD $) In Thousands, except Share data, unless otherwise specified	9 Months Ended			9 Months Ended		9 Months Ended
	Sep. 30, 2013 tranche	Dec. 31, 2012	Sep. 30, 2013 NHPPMBLP [Member]	Sep. 30, 2013 NHPPMBLP [Member] Class A Units	Oct. 31, 2013 NHPPMBLP [Member] Class A Units	Sep. 30, 2013 NHPPMBLP [Member] Class B Units	Oct. 31, 2013 NHPPMBLP [Member] Class B Units
Redeemable Noncontrolling Interest [Line Items]
Limited partnership units held by third party investors (in shares)				2,300,419
Percentage of ownership interest on total units outstanding				27.20%		72.80%
Limited partnership units outstanding (in shares)						6,148,481
Number of entity shares issued in exchange for redemption of OP Units			$ 0.7866
Limited Partners' Capital Account, Units Issued					158,459
General Partners' Capital Account, Units Issued							132,350
Fair value of operating partnership units exceeding cost	$ 111,700	$ 114,900
Number of foreign currency tranches reported at fair value	2