UNAUDITED CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - shares shares in Thousands	Mar. 31, 2017	Dec. 31, 2016
Statement Of Financial Position [Abstract]
Common limited partner capital (in shares)	72,313	72,111
Common limited partner capital (in shares)	72,313	72,111
General partner interests (in shares)	1,476	1,471
General partner interests (in shares)	1,476	1,471

The number of limited partner units outstanding.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 272
-SubTopic 10
-Section 50
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=6373374&loc=d3e70434-108055

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 5
-Subparagraph (SAB Topic 4.F)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187171-122770

Name:	us-gaap_LimitedPartnersCapitalAccountUnitsOutstanding
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant