Condensed Consolidating Statement of Cash Flows (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	$ 8,459	$ 3,975
Cash Flows From Investing Activities:
Cash paid for acquisitions and capital expenditures	(7,156)	(7,250)
Net cash used in investing activities	(7,156)	(7,250)
Cash Flows From Financing Activities:
Cash distributions	(44,703)	(36,297)
Net borrowings and repayments of debt	(36,503)	42,608
Proceeds from issuance of common units	74,537
Other financing activities	(351)	(34)
Net cash provided by (used in) financing activities	(7,020)	6,277
Net increase (decrease) in cash and cash equivalents	(5,717)	3,002
Cash and cash equivalents - Beginning of period	15,153	10,401
Cash and cash equivalents - End of period	9,436	13,403
Consolidation, Eliminations
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	(9,515)	(43,188)
Cash Flows From Investing Activities:
Payments to affiliates	32,458
Net cash used in investing activities	32,458
Cash Flows From Financing Activities:
Payments from affiliates	(22,943)	43,188
Net cash provided by (used in) financing activities	(22,943)	43,188
Parent
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	2,624	36,297
Cash Flows From Investing Activities:
Payments to affiliates	(32,458)
Net cash used in investing activities	(32,458)
Cash Flows From Financing Activities:
Cash distributions	(44,703)	(36,297)
Proceeds from issuance of common units	74,537
Net cash provided by (used in) financing activities	29,834	(36,297)
Subsidiary Issuer
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	61	151
Cash Flows From Investing Activities:
Cash paid for acquisitions and capital expenditures	(61)	(151)
Net cash used in investing activities	(61)	(151)
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	13,804	9,324
Cash Flows From Investing Activities:
Cash paid for acquisitions and capital expenditures	(5,380)	(5,472)
Net cash used in investing activities	(5,380)	(5,472)
Cash Flows From Financing Activities:
Payments from affiliates	22,943	(43,188)
Net borrowings and repayments of debt	(36,503)	42,608
Other financing activities	(351)	(34)
Net cash provided by (used in) financing activities	(13,911)	(614)
Net increase (decrease) in cash and cash equivalents	(5,487)	3,238
Cash and cash equivalents - Beginning of period	11,869	7,059
Cash and cash equivalents - End of period	6,382	10,297
Non-Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
Net cash provided by (used in) operating activities	1,485	1,391
Cash Flows From Investing Activities:
Cash paid for acquisitions and capital expenditures	(1,715)	(1,627)
Net cash used in investing activities	(1,715)	(1,627)
Cash Flows From Financing Activities:
Net increase (decrease) in cash and cash equivalents	(230)	(236)
Cash and cash equivalents - Beginning of period	3,284	3,342
Cash and cash equivalents - End of period	$ 3,054	$ 3,106