Fair Value Measurements and Derivative Instruments (Available-for-sale Securities Maturities) (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Amortized cost
Within 1 year	$ 26,602
After 1 year through 5 years	49,024
After 5 years through 10 years	61,991
After 10 years	124,071
Total	261,688	$ 218,512
Estimated fair value
Within 1 year	26,831
After 1 year through 5 years	50,100
After 5 years through 10 years	61,909
After 10 years	128,120
Total	$ 266,960	$ 222,120

Amortized cost of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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