The number of securities classified as temporary equity that have been issued and are held by the entity's shareholders. Securities outstanding equals securities issued minus securities held in treasury. Temporary equity is a security with redemption features that are outside the control of the issuer, is not classified as an asset or liability in conformity with GAAP, and is not mandatorily redeemable. Includes any type of security that is redeemable at a fixed or determinable price or on a fixed or determinable date or dates, is redeemable at the option of the holder, or has conditions for redemption which are not solely within the control of the issuer. If convertible, the issuer does not control the actions or events necessary to issue the maximum number of shares that could be required to be delivered under the conversion option if the holder exercises the option to convert the stock to another class of equity. If the security is a warrant or a rights issue, the warrant or rights issue is considered to be temporary equity if the issuer cannot demonstrate that it would be able to deliver upon the exercise of the option by the holder in all cases. Includes stock with put option held by ESOP and stock redeemable by holder only in the event of a change in control of the issuer.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(27)(b))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

Partners' Capital, Mezzanine Equity and Distributions (Change in Class A Convertible Preferred Units) (Details) - USD ($) $ in Thousands	1 Months Ended			9 Months Ended
	Jul. 31, 2018	May 01, 2018	Jan. 31, 2018	Sep. 30, 2018
Mezzanine Capital Balance
Balance as of December 31, 2017			$ 697,151	$ 697,151
Balance as of September 30, 2018				$ 744,727
Number of Class A Convertible Preferred Units
Balance as of December 31, 2017			22,411,728	22,411,728
Balance as of September 30, 2018				23,914,890
Class A Convertible Preferred Stock Units
Mezzanine Capital Balance
Balance as of December 31, 2017			$ 697,151	$ 697,151
Distributions paid-in-kind	$ 17,300	$ 16,900	$ 16,500	50,671
Allocation of Distributions paid in-kind to Preferred Distribution Rate Reset Election (Note 16)				(3,095)
Balance as of September 30, 2018				$ 744,727
Number of Class A Convertible Preferred Units
Balance as of December 31, 2017			22,411,728	22,411,728
Distributions paid-in-kind	511,934	500,976	490,252	1,503,162
Balance as of September 30, 2018				23,914,890