2. Recent Accounting Pronouncements 2. Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Jan. 01, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets	$ 166,512		$ 0
Operating lease liabilities	$ 143,318
Accounting Standards Update 2016-02 [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets		$ 140,700
Operating lease liabilities		$ 119,900