Income Taxes - Schedule of Reconciliation of Gross Liability for Uncertain Tax Positions (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Uncertain tax position liability at the beginning of the year	$ 3,677
Increases resulting from merger transaction	22,605
Increases related to tax positions taken during the current period	1,847
Decreases related to tax positions taken during prior periods	(2,440)
Decreases related to settlements with taxing authorities	(806)
Decreases related to expiration of statute of limitations	(1,625)
Uncertain tax position liability at the end of the year	$ 23,258