Description of Business and Summary of Significant Accounting Policies (SBC) (Details)	12 Months Ended
Dec. 31, 2015
Stock-Based Compensation
Percentage of period from the vesting date added for determination of weighted average expected life	50.00%

Represents the percentage of period from the vesting date added to vesting period for determination of expected term of share-based compensation awards.

No definition available.

Name:	ctrl_ShareBasedCompensationArrangementByShareBasedPaymentAwardPercentageOfPeriodFromVestingDateAddedForDeterminationOfFairValueAssumptionsExpectedTerm
Namespace Prefix:	ctrl_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration