Investments in Unconsolidated Affiliates Narrative (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended
	May. 05, 2016	Apr. 30, 2016	Mar. 31, 2016	Mar. 31, 2015
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments			$ 5.5	$ 18.1
Jackalope Gas Gathering Services, L.L.C.
Schedule of Equity Method Investments [Line Items]
Proceeds from equity method investments			5.1
Amortization			0.1	0.8
Tres Palacios Holdings LLC
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments			5.5	5.7
Amortization			0.3	0.3
Powder River Basin Industrial Complex, LLC
Schedule of Equity Method Investments [Line Items]
Proceeds from equity method investments			0.6	0.3
Payments to acquire equity method investments				3.7
Amortization			$ 0.4
Crestwood Niobrara LLC | Jackalope Gas Gathering Services, L.L.C.
Schedule of Equity Method Investments [Line Items]
Payments to acquire equity method investments				$ 8.8
Subsequent Event | Jackalope Gas Gathering Services, L.L.C.
Schedule of Equity Method Investments [Line Items]
Proceeds from equity method investments	$ 7.0
Subsequent Event | Tres Palacios Holdings LLC
Schedule of Equity Method Investments [Line Items]
Proceeds from equity method investments		$ 4.1