Annual report pursuant to Section 13 and 15(d)

Subsequent Events (Details)

v3.6.0.2
Subsequent Events (Details)
$ / shares in Units, $ in Millions
12 Months Ended
Feb. 10, 2017
USD ($)
shares
Feb. 09, 2017
shares
Feb. 06, 2017
USD ($)
Jan. 11, 2017
$ / shares
Nov. 24, 2016
$ / shares
Aug. 24, 2016
$ / shares
May 25, 2016
$ / shares
Feb. 29, 2016
$ / shares
Nov. 30, 2015
$ / shares
Aug. 27, 2015
$ / shares
May 27, 2015
$ / shares
Feb. 27, 2015
$ / shares
Dec. 31, 2016
shares
Dec. 31, 2015
shares
Dec. 31, 2014
shares
Subsequent events                              
Cash distribution declared | $ / shares         $ 0.2650 $ 0.2500 $ 0.2350 $ 0.2200 $ 0.2050 $ 0.1900 $ 0.1800 $ 0.0943      
Subordinated units                         75,941,000 75,941,000 75,941,000
Subsequent event                              
Subsequent events                              
Cash distribution declared | $ / shares       $ 0.28                      
Subordinated units   75,940,957                          
Common units conversion ratio   1                          
Number of shares of common stock sold 6,900,000                            
Net proceeds received from issuance shares of common units | $ $ 223                            
Subsequent event | Appalachia Joint venture                              
Subsequent events                              
Ownership percentage     50.00%                        
Percentage of interest held by joint venture in third party fractionator in Ohio     33.33%                        
Contribution to joint venture | $     $ 155                        
Subsequent event | Appalachia Joint venture | Mark West                              
Subsequent events                              
Ownership percentage     50.00%