Related Party Transactions (Affiliated Notes Receivable) (Details) - Affiliated Entity - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Related Party Transaction [Line Items]
Total long-term notes receivable - affiliated	$ 40,925	$ 37,340
U.S. Dollar floating rate notes
Related Party Transaction [Line Items]
Total long-term notes receivable - affiliated	$ 0	24,203
U.S. Dollar floating rate notes | Minimum
Related Party Transaction [Line Items]
Interest Rates	1.36%
U.S. Dollar floating rate notes | Maximum
Related Party Transaction [Line Items]
Interest Rates	1.77%
U.S. Dollar fixed rate notes
Related Party Transaction [Line Items]
Total long-term notes receivable - affiliated	$ 40,925	10,423
U.S. Dollar fixed rate notes | Minimum
Related Party Transaction [Line Items]
Interest Rates	2.31%
U.S. Dollar fixed rate notes | Maximum
Related Party Transaction [Line Items]
Interest Rates	14.85%
Euro-denominated fixed rate notes
Related Party Transaction [Line Items]
Interest Rates	2.30%
Total long-term notes receivable - affiliated	$ 0	$ 2,714