Annual report pursuant to Section 13 and 15(d)

Commitments and Contingencies - Narrative (Details)

v3.3.1.900
Commitments and Contingencies - Narrative (Details) - USD ($)
$ in Millions
12 Months Ended
Dec. 31, 2015
Dec. 31, 2014
Dec. 31, 2013
Loss Contingencies [Line Items]      
Operating Leases, Rent Expense $ 6.4 $ 6.0 $ 5.8
Purchase commitments to complete construction 56.0    
Partnership Interest [Member]      
Loss Contingencies [Line Items]      
Purchase commitments to complete construction 48.9    
Company's Share of Joint Venture Purchase Commitment Remaining Minimum Amount Committed $ 24.4