Annual report pursuant to Section 13 and 15(d)

Income Taxes (Reconciliation of Unrecognized Tax Benefits) (Details)

v3.8.0.1
Income Taxes (Reconciliation of Unrecognized Tax Benefits) (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2017
Dec. 31, 2016
Dec. 31, 2015
Income Tax Disclosure [Abstract]      
Balance at beginning of period $ 9,998 $ 11,187 $ 6,630
Increases related to prior year tax positions 858 2,514 365
Decreases related to prior year tax positions (2,895) (5,119) (2,019)
Increases related to current year tax positions 2,714 1,599 6,564
Expiration of statute of limitations (163) (183) (353)
Balance at end of period $ 10,512 $ 9,998 $ 11,187