Derivatives (Gains/(Losses) on Derivatives Associated with Cash Flow Hedges) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Derivative Instruments, Gain (Loss) [Line Items]
Gain/Loss expected to be reclassified to earnings in the next twelve months				$ 800
Cash Flow Hedge | Hedging Instruments | Interest Rate Swap
Derivative Instruments, Gain (Loss) [Line Items]
Gains/(Losses)	[1],[2]	$ 3,491	$ 1,988	$ 390	$ 7,606

[1] Amount represents the pre-tax gains/(losses) included within AOCI.

[2] Includes approximately $0.8 million of losses expected to be reclassified into earnings in the next twelve months.