Current Accounting Developments (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2017	Jun. 30, 2017
Accounting Policies [Abstract]
Net excess tax benefits for restricted stock units	$ 49	$ 4,463

Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount

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