Derivatives (Interest Rate Swap) (Details) - Interest Rate Swaps - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Sep. 24, 2018		Apr. 01, 2015
Derivative [Line Items]
Derivative, fixed interest rate		6.19%	[1]	4.85%
Senior Loans
Derivative [Line Items]
Derivative, floor interest rate at a future date		3.19%
Senior Loans | Cash Flow Hedging
Derivative [Line Items]
Derivative, notional amount		$ 200.0		$ 220.0
Interest Expense | Cash Flow Hedging
Derivative [Line Items]
Gain (loss) to be reclassified from AOCI into earnings within 12 months	$ 1.4

[1] Upon refinancing our Term Loan B, the fixed interest rate will be 3.19 percent plus the new refinanced credit spread.