Quarterly report pursuant to Section 13 or 15(d)

Debt (Revolving Credit Agreement) (Details)

v3.7.0.1
Debt (Revolving Credit Agreement) (Details) - Revolving credit agreement
6 Months Ended
Jun. 30, 2017
USD ($)
Dec. 31, 2016
USD ($)
Debt Instrument [Line Items]    
Maximum borrowing capacity $ 1,000,000,000  
Borrowings outstanding $ 150,000,000 $ 100,000,000
Weighted average interest rate (percent) 4.75%  
Ratio of debt to EBITDA, after current year 3.0