New Accounting Standards (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	$ 155,100
Total lease liabilities	$ 206,763
ACS 842
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease assets		$ 148,500
Total lease liabilities		$ 206,700
Deferred rent and cease-use liabilities			$ 62,300
Prepaid rent			$ 4,100