Fair Value Measurements and Derivative Instruments (Available-for-sale Securities Maturities) (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Amortized cost
Within 1 year	$ 26,274
After 1 year through 5 years	56,027
After 5 years through 10 years	47,838
After 10 years	112,315
Total	242,454	$ 218,512
Estimated fair value
Within 1 year	26,407
After 1 year through 5 years	58,709
After 5 years through 10 years	49,663
After 10 years	114,760
Total	$ 249,539	$ 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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